Screen inverter board
Laptop inverter boards (also know as LCD inverter, FL inverter, screen inverter, backlight inverter) come in different shapes and sizes. On the picture above you see some typical looking inverter boards found in laptop computers.
The inverter board works as a power supply for the backlight lamp mounted inside the LCD screen. The inverter board converts low voltage DC power (few volts) supplied by the motherboard to high voltage AC power (few hundred volts) needed for the backlight lamp.
When the inverter board works properly, the backlight lamp gets power and the LCD screen lights up. As a result, the image on the screen is bright.
HOW INVERTER CONNECTED TO LDC SCREEN
On the picture below you can see a typical laptop display assembly which includes the LCD screen, video cable and inverter board.
One side of the inverter board connects to the backlight lamp and another side to the video cable (LCD screen cable).
HOW INVERTER MOUNTED INSIDE LAPTOP DISPLAY PANEL
In most laptops the inverter board is mounted below the LCD screen as it shown on the picture below. You can get an access to the inverter board when you remove the screen bezel – a plastic frame around the LCD screen.
TYPICAL INVERTER FAILURE SYMPTOMS
Usually inverters fail in one of the following ways:
1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.
2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.
3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.
Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.
Need spare parts for your laptop?
If you are looking for spare parts for your laptop you can find brand new and used parts here. Just search by the part name and laptop model.
January 15th, 2009 at 3:46 pm
MY laptop works fine on battery but as soon as I plug the power cord it goes dark. Could this be a problem with the inverter board.
January 15th, 2009 at 4:18 pm
Gauntlett,
Does it go completely dark so you cannot see the image at all, or the screen just gets darker but still readable? I’m thinking maybe your problem is related to the power settings. It’s possible that screen brightness is set to minimum for the AC mode.
January 15th, 2009 at 10:45 pm
Hello, I have an old dell latitude c640 that notebook and it runs really well, but the screen has a vertical dark patch coming from the bottom-middle of my screen. It is darkest at that spot and changing the screen brightness works every were except that spot. Is this a backlight or inverter problem?
January 15th, 2009 at 11:16 pm
Dominick,
If the screen lights up and you can see the image, there is no problem with the inverter board or backlight lamp. From the provided description it sounds like you have a problem with the LCD screen.
January 22nd, 2009 at 4:29 pm
My HP Pavilion dv9000 notebook is not in warranty anymore. A few month ago I turned it on and noticed a very think line on the left side of the screen. The line didn’t go away after I reformatted the notebook. About two week later two more lines appeared close to the first one. Now I have even more lines.
As you said, I tried my notebook with desktop monitor. There no lines on the monitor, I see them only on laptop screen.
Do you you think my inverter is going bad?
January 23rd, 2009 at 1:49 pm
Mary,
That is a very typical LCD screen failure description.
I’m 100% sure this problem is not related to the inverter board failure. You have a problem with the LCD screen and it has to be replaced.
January 25th, 2009 at 12:56 pm
My girlfriends HP Pvilion DV9000 has a problem with all of the white on the screen being “pink” and fuzzy looking. I have tried a different video card and it looks the same.
January 25th, 2009 at 10:04 pm
William Silva,
I assume this problem appears even before Windows starts loading. It’s not software related, right?
From my experience I can tell that pinkish tone on white backgrounds might indicate a problem with the backlight lamp but you also mentioned that the image is fuzzy looking and that could be a problem with the LCD video cable.
It looks like you know how to disassemble the laptop, here are instructions for a Pavilion dv9000 just in case.
You can try replacing the video cable. Before you replace the cable, try reseating connectors on the motherboard and LCD screen. Maybe it’s just a connection related issue. Test the laptop after you reconnected the cable.
If a new cable will not fix the problem, I guess you’ll have to replace the LCDs screen.
January 27th, 2009 at 10:29 am
I have an issue with my HP Pavilion dv9000 that matches the symptoms of a typical inverter failure (the first description). I ordered a new inverter from HP and installed it and it is still having the same issue. What should be the next thing I replace? The bulbs?
January 27th, 2009 at 11:27 am
When I start my laptop, for a fraction of second Ill get the light on the screen but after that it will become dark( But still everything will display on the screen. Is it possible that for a fraction of second I am getting backlight it means lcd bulb is fine but the inverter is bad??
January 27th, 2009 at 11:40 am
Adam,
You are correct. If you installed a new inverter board but still experience the same problem, probably it’s a bad backlight lamp.
It’s not easy to replace the backligth lamp and you can damage the screen, so it might make sense to replace the whole LCD.
By the way, did you know that HP repairs some out of warranty Pavilion dv9000 laptop at no charge? Here you’ll find more information about free repair from HP. Maybe you can get your laptop fixed at no charge?
January 27th, 2009 at 11:42 am
Mitul,
You cannot tell without testing the laptop with another working inverter or backlight lamp. Could be either one.
If you have to guess, go with the inverter first. It’s way easier to replace and is shouldn’t be very expensive.
January 29th, 2009 at 8:53 am
Hello,
I have a hp compaq 8510p, and it have problem with inverter. I was trying to replace inverter, but unfortunately I couldn’t find any store sold hp compaq 8510p inverter.
I have read manual, and found that this 8510 series have a dedicated inverter.
However, I wonder if can I use other hp laptop series inverter to replace for this 8510 series inverter.
I hope someone can tell me which inverter compatible with this 8510 series.
Thanks!
January 29th, 2009 at 9:58 am
Duc,
The best way to find a new compatible inverter would be searching by the HP spare part number from the old inverter. Take a closer look at the original inverter. Can you see the spare part number on it? Google this number.
According to the HP hardware and service guide for HP Compaq 8510p notebook PC, there is only one inverter listed for this model. Here’s the part number: 452214-001
Google this part number and you’ll find your inverter.
By the way, you’ll find inverter replacement instructions in the maintenance and service guide on the page 48.
January 29th, 2009 at 10:27 am
Hello,
in august 2006 I bought a Pavilion DV6560EL. I never had a problem with it until a couple of months ago, when I noticed a slightly reduced brightness of the lcd panel, but I didn’t think too much at it since I wasn’t really sure about it. Then, some weeks ago, I started experiencing another annoying problem: basically, at random periods, the screen starts flickering…in other words, brightness increases and diminishes itself just a little bit for some seconds and then returns at the right level. I have to say that, sometimes, when the laptop comes back from hibernation, I can’t change the brightness level either from keyboard or vista’s “laptop center” applet (in these situations it disappears from the panel!!), but I really don’t know if it’s a problem related to the flickering.
I sent an email to HP support describing the problem and they answered that I should try unplugging the power cable for about two hours, then press the power button for a minute, and finally replug the power cable, I tried it but it’s always the same. Could it be an inverter problem?
Thanks, and compliments for the great website!
January 29th, 2009 at 11:26 am
Gianni,
1. Your problem could be related to the DC-IN power jack – the socket where you plug in the power adapter. It’s possible that the power jack is loose or broken and the laptop intermittently looses connection with the AC adapter and switches between AC mode and battery mode. Apparently the screen becomes dimer when the laptop switches to the battery mode because the screen brightness is set to lower level for this mode.
Here’s what you can do. Plug in the AC adapter and wiggle the plug inside the power socket. Does the laptop looses AC power when you wiggle the plug? Does the LCD screen flicker when you wiggle the plug?
If it does, your problem could be related to the DC jack or maybe the AC adapter has a damaged cord.
2. If there is nothing wrong with the power socket and the laptop not loosing power when you wiggle the adapter plug, there is a chance that you have a faulty inverter board.
By the way, check out the link I posted in the comment #11. Maybe your dv6560 qualifies for a free repair.
January 29th, 2009 at 12:27 pm
I forgot to say that I tried all different power combinations (only with battery/only AC adapter/both) but the problem didn’t disappear; it could really be the inverter board.
Unfortunately, my laptop is not in the list of the eligible models, anyway, I’ll write back to the HP support to let them know that their suggestions didn’t work. I’ll keep you informed!
Thanks a lot for the answer, and keep up the good work!
January 29th, 2009 at 12:40 pm
Gianni,
So, it’s not related to the DC-IN power jack then. I guess it’s either a failing inverter board or there is something is wrong with the screen.
January 29th, 2009 at 7:26 pm
Thank you very much!
I have just order a new 452214-001 inverter.
January 29th, 2009 at 7:36 pm
You are welcome! I hope this inverter works well and fixes your problem with the screen.
January 30th, 2009 at 2:15 am
When ever I fire up my laptop I have to wiggle the screen back and forth to get the image to stay on the screen. Once you get it into just the right place the display is fine. It continously freezes though till you wiggle it again then it will pick up wherever you are. The issue has continously gotten worse. If you mess with it enough eventually you get all lines and a crazy display. Does this sound like a screen or a wiring issue? I already checked where the video cord plugs into the motherboard. Warranty is out and I need my laptop back! Thanks
January 30th, 2009 at 1:21 pm
I have a dead acer laptop with (what I thought was) a working screen. I had a customer with a Compaq laptop with a nearly identical lcd screen that was cracked. I tried connecting my screen to the compaq, but no video came up and the inverter seemed to start to heat up. I immediately powered it off and later tried plugging it back into the dead acer (bad ata controller, actually works with usb boot media)
now I get no video whatsoever on the LCD but external monitor works fine. Have I fried my LCD screen and/or inverter? any thoughts appreciated
January 30th, 2009 at 1:46 pm
Joey,
To me that description sounds like a problem with the LCD cable, apparently it’s defective and has to be replaced. I guess could be a problem with the LCD, but for some reason it feels like bad cable.
By the way, did you test the laptop with an external monitor? Can you tell if the external video output works fine even though the internal video fails? If you are getting the same exact problem on both the internal and external screens, there could be a problem with the video card. It’s possible that when you are moving the display, you are actually flexing the motherboard and temporarily fixing the problem.
Test your laptop with an external monitor and let me know if it fails the same way as the internal screen.
January 30th, 2009 at 2:18 pm
ACH,
First of all, check the cable connection. Maybe it’s not plugged correctly. Try reconnecting the video cable.
When you moved your LCD screen to the Compaq laptop you tried to turn it on with the customer’s inverter, right? It means, your inverter board stayed connected to the Acer and you couldn’t damage it. Am I missing something?
Take a closer look at the LCD on your Acer. Is it completely blank and black? Can you see any faint image at all?
If you cannot see any image and reconnecting the video cable doesn’t help, apparently you damaged the screen when tested it with the Compaq laptop. Even though both LCD screens look very similar, they might require different video cables. Connecting a good working LCD screen to a laptop with incompatible video cable can damage the screen.
January 31st, 2009 at 7:54 pm
Repair guy I took the bevel from around the screen off today as well as the plastic piece from above the keyboard. I fired it up and wiggled and messed with all the wires. Moving wires did nothing but as I moved the screen the display would change. It’s totally out now. I have an S video cord connection on my machine but last time I messed with it I had to set it up on the settings so I don’t know if I can just plug it in and get it to work on my TV to test it. BTW the machine is a HP DV5000 series. It’s about 2 years old.
January 31st, 2009 at 11:19 pm
Joey,
Apparently it’s a bad screen.
It’s easier to test with a desktop monitor. Can you find a monitor for the test?
You cannot tell if it’s a bad screen or motherboard until you test the external video output.
February 1st, 2009 at 3:32 am
My screen is dark and can barely see the picture, I’ve changed the LCD and inverter but no luck, can somebody please help!, is there anyway I can check whether power is getting to the inverter.
February 1st, 2009 at 10:01 am
Bradley,
I think it’s possible to check voltage with a multimeter on the left side of the inverter board where it’s connected to the LCD cable. I believe you have to measure voltage between pin 1 and ground, but I’m not sure 100%. You’ll have to get some low voltage DC readings. If there is no incoming voltage, it could be bad LCD cable or motherboard.
Did you try reconnecting the LCD cable connection on the motherboard? Maybe it’s loose connection?
February 1st, 2009 at 1:17 pm
I’ve measured the voltage on the left hand side, not quite sure which is pin1 and ground but I do get a reading of 3 volts implying power is getting to the inverter, maybe the new inverter I’ve bought is dead??, is it easy to get to the motherboard connection? Do I have to take the all the back off? If power is getting to the inverter is it neccesary to check the connection to the motherboard.
February 1st, 2009 at 1:31 pm
Bradley,
I’m not sure but 3 volts seems to be low. I don’t have a multimeter with me and cannot confirm if that voltage is correct.
It’s possible. I’ve seen that happening before. Did you but it from a reliable source?
It depends on the laptop model. On some laptops this connector could be found under the keyboard bezel. On other models it’s located under the keyboard.
No, but you’ll have to remove the keyboard bezel and maybe the keyboard too.
In your case it looks like the power is getting to the inverter, so I assume the cable is seated correctly. Again, 3 volts seems to be low. I believe when I tested it last time (a couple of years ago), I was reading over 9 volts.
By the way, do you have a display close switch on your laptop – a small button usually located close to one of the hinges. When the display is closed, the button is pressed down and there is no voltage going to the inverter. Check the button. Maybe it’s dirty and got stuck inside the case and the laptop “thinks” the display is closed even though it’s open.
February 1st, 2009 at 1:51 pm
Managed to get to the connection, everything there looks ok. Got the inverter of eBay so not reliable so I’ve emailed them back asking for a refund. I’ve got another laptop I’ll see what reading I’m getting with that, if it is reading higher what does that mean?? I’ve tried the laptop close switch was one off my first thoughts. Will let you know the reading
February 1st, 2009 at 2:16 pm
Yep took a reading of another laptop and getting around 16volts any ideas???
February 1st, 2009 at 2:25 pm
Gareth,
Yep, 16volts sounds normal.
I guess there could be a problem with the motherboard. For some reason it’s not providing enough power for the inverter board and because of that the backlight will not light up. That’s my guess but I could be wrong.
I don’t think it’s a cable related problem. With bad cable you would get no voltage at all, but you are reading 3volts. Apparently it’s not the cable.
February 1st, 2009 at 2:30 pm
This is strange, when I got the new LCD display I just connected the cables to see if it worked and it was fine, the following day I fitted the screen in the laptop and this is when the problem occurred, I can’t understand why it has gone dim, when that was the oringinal fault it was a cracked LCD
February 1st, 2009 at 2:38 pm
Gareth,
Did the backlight worked after you cracked the screen? Do you still have the cracked screen (hopefully with a good backligth) lamp?
Can you install the cracked screen back and see if the backlight still works?
February 1st, 2009 at 2:46 pm
Original fault was cracked LCD, the backlight did work it was just the screen that was cracked, I’ve still got it and plugged it back in but the backlight on that will not light up. That’s why this is strange, I’m at a complete loss with this one, the only over thing I can think off is to replace the motherboard but that’s too expensive so that’s a no no
February 19th, 2009 at 6:38 pm
Hi.
Whenever I have my laptop plugged in to the AC Adapter, my backlight will eventually turn off and will not turn on until after I have restarted or place the computer in sleep mode. However, when it runs on battery, I have yet to see my backlight turn off. Could this still be an inverter problem?
February 20th, 2009 at 4:18 pm
Same problem as Bradley here
Guys I have been googling since 2 days to find a solution to my strange problem.bingo! i hit this page.I am experiencing the same problem as u Bradley.No enough power to the inverter from the motherboard! I read some where for IBm laptops there is something called LVDS board which they can replace(where the female pin for the video / inverter cable fits).Do we got any for our acer aspire 5100? .or can we shunt power some where else from the motherboard?
February 24th, 2009 at 8:48 pm
Gareth Bradley,
If I understand correctly, you bought a new LCD screen but the backlight will not light up? Try installing the old (cracked) screen back into the laptop. Will it light up?
If the backlight works fine on the cracked screen but not on the new one, apparently it’s either defective LCD screen or the screen is not compatible with the laptop.
February 24th, 2009 at 8:56 pm
Roman,
It’s hard to tell which one is causing the problem, the backlight lamp or inverter board.
Here’s what you can try.
Try reducing the LCD screen brightness for the AC mode (when the AC adapter is plugged in). On some laptops you can do that through the power management software in the control panel, on other laptops you can do that through a keyboard shortcut or in the BIOS settings. Make the LCD screen a little bit dimmer when the laptop is plugged into the adapter. Will it help the backlight to stay on all the time or it still turns off even thought the brightness is reduced?
February 24th, 2009 at 9:02 pm
swarup,
What is your problem? Bradley had a cracked screen and the new one didn’t light up. Do you have the same problem?
If the LCD screen in your laptop works but it’s very dim, most likely you have a faulty inverter board. I would try replacing the inverter first. Here’s disassembly guide for an Acer Aspire 5100 laptop.
How to remove LCD screen and replace inverter board in Acer Aspire 5100 laptop
February 27th, 2009 at 8:14 am
You can use this guide for replacing inverter in a HP Compaq 8510p and 8510w:
How to open display and replace inverter board in HP Compaq 8510p and 8510w notebook
Dan
March 2nd, 2009 at 7:20 am
I’ve got an HP DV6000. When I power it on, I get nothing on the screen. Totally black.
I pulled the panel off and I thought where the main flat LCD cable plugs into the motherboard, the wires in the cable might have gotten pinched or something becuase I saw the screen come on once or twice when working on it.
I replaced the LCD’s ribbon cable and tested it and it fired up fine.
I re-assembled the laptop and now there’s nothing on the screen again. I was very gentle with the cable when re-assembling.
Furthermore, nothing appears on an external monitor when the laptop is powered on. the external LCD screen just sits there in power save mode.
Any ideas? I’ve tried on both AC and battery power and nothing. I wouldn’t think it’s the internal video device because I’ve seen the screen work. I guess I could always be wrong though…
If you have any ideas please help!
March 2nd, 2009 at 9:43 am
Drew,
If both the internal and external video do not work, your problem is not related to the display panel. It could be either bad memory or motherboard. Try reconnecting memory modules.
If you have two modules, remove them one by one. Test the laptop with each module separately.
Read this article: Free repair for some out-of-warranty HP Pavilion and Compaq Presario laptops. Maybe you can get a free repair from HP?
March 9th, 2009 at 7:24 am
I have a Compaq Presario R3425 with what sounds like a bad inverter. However, in addition to the screen being very dim, the wireless internet no longer works. I have heard that the antennae for the wireless modem runs along the perimeter of the screen. Could the bad inverter also be tied into the wireless antennae?
March 9th, 2009 at 7:35 am
Andy,
Nope, these two problems are not related. A bad inverter board cannot kill wireless connectivity.
March 9th, 2009 at 9:41 am
This is great news!
I have a Dell Inspiron 6000 that does exactly what you described in failure symptom #1.
My laptop screen stays on for about 30 secs after reboots then goes black. It also comes back on if I close the display lid and reopen it, but only for 30 secs. Could this be related to the Lid Close Switch?
Computer works fine with an external display.
I’m guess I’ll try to check the switch 1st. If that doesn’t work I’ll try to replace the inverter and bulb if necessary.
Where can I buy these parts?
Great article! Thanks.
-Justin
March 10th, 2009 at 10:38 am
I have a Compaq nx7300 (1.5 years old) and recently, I dropped my laptop on the ground. When I turned it back on, the screen was very dim although I can still see the images. I tried to adjust the dimmer but it didn’t lighten the screen. I then hooked the computer up to an external monitor and the image was able to display properly on the external monitor. I tried getting help from the tech support at my college, but they didn’t really do much and they told me that most likely it would cost 400 dollars to fix it. Unfortunately, it’s out of my budget. After reading about inverters and backlights, I am wondering if something is wrong with the inverter and if there could also be something wrong with the backlight. What would you advise me to do?
March 10th, 2009 at 10:57 pm
Justin Lancaster,
I don’t think so. Sounds like a faulty inverter board or bad backligth lamp.
I would definitely try replacing the inverter first.
You can find a new inverter or LCD with inverter for Inspiron 6000 here.
March 10th, 2009 at 11:09 pm
Jun,
Most likely you damaged the backlight lamp.
You can check the cables connected to the inverter board and try reconnecting. Maybe one of the cables is loose.
If it doesn’t help, apparently your failure is related to the backlight lamp.
The backlight lamp is mounted INSIDE the LCD screen and it’s very hard to replace. If you’ve never done it before, I would recommend replacing the whole LCD screen. You can find a new screen for your laptop here, it’s about $60-70.
You’ll find display disassembly and LCD replacement instructions in the maintenance and service guide for HP Compaq nx7300 and nx7400 notebooks. Here’s the link. Take a look at the page 214. It’s a pdf file and may take a while to download.
March 11th, 2009 at 10:10 am
Thanks Repair Man! Just ordered an inverter, I’ll let you know how it goes.
Is there any software that needs to be updated when replacing an inverter? Like a driver or something?
March 11th, 2009 at 10:15 am
Justin Lancaster,
Nope, it’s plug-n-play.
Hopefully, it fixes your backlight problem. Just be careful taking it apart. Proceed on your own risk.
March 11th, 2009 at 5:53 pm
Thanks a lot Repair Man! I really appreciate your helpfulness and thoughtful response!
Jun
March 16th, 2009 at 6:21 am
Hi,
My HP dv5000 had all the same symptoms. I replaced the inverter, worked great for a few hours. I heard some barely audible crackling noise, no burning smell, then the screen started the flickering, and soon after went out again. Is it likely I bought a bad inverter, or could something else be causing the inverter to go out?
Ron
March 17th, 2009 at 9:36 pm
Ron,
Probably it’s just a defective inverter. Try replacing it again.
March 25th, 2009 at 2:28 pm
Hey Guys, looks like my hp pavilion n5470 has all the symptoms of a bad inverter board, if anybody could direct me to an online repair guide for my hp it’d be greatly appreciated, a good site I could buy one from too would be super helpful….
thanks for all the great info,
jesse
jessehoffphotography
jessehoff.com
March 25th, 2009 at 8:53 pm
Hi,
My compaq nx7400 no longer lights up. I spilled a little water on the back of the screen cover, while it was closed, and since then it will not illuminate. If held at the right angle i am able to barely make out whats on the screen. Also, it works fine hooked to an external monitor. I read some of your previous posts and went ahead and took the screen apart. When I looked at the inverter it seemed to have a little bit of a build up on some of the solder. i am assuming the water made its way into the inverter somehow but am not sure. i hooked up a meter and there is power to it. I have ordered an inverter and a new bulb. Any other suggestions as to what it may be? Thank you
March 25th, 2009 at 9:29 pm
jesse,
I posted a bunch of HP disassembly instructions on Inside My Laptop.
The display disassembly instructions will be very similar for most laptops, not only HPs. Take a look at a few display disassembly guides and you’ll see what I’m talking about.
Basically, all you have to do is remove the screen bezel and replace the inverter.
March 25th, 2009 at 10:04 pm
Jason,
I would definitely try replacing the inverter board first. It takes only a couple of minutes and you have a very good chance to fix the problem.
April 7th, 2009 at 6:09 pm
The backlight on my Dell Inspiron 8500 went black, but barely viewable, the other day. After some research, it sounded like an inverter problem as it usually works for about 30 seconds after a reboot then goes black and an external display works perfectly fine. I bought an inverter from a local laptop store and it still wouldn’t work. I even brought it back for a replacement and I still have the same result. Any thoughts or suggestions as to where I could find the right hardware?? Thanks!
April 7th, 2009 at 7:15 pm
James,
Most likely your problem is related to the backlight lamp which is located inside the LCD screen. You can try replacing the backlight lamp yourself but it’s not easy. If you cannot do that, I would suggest replacing the whole LCD screen.
April 15th, 2009 at 6:17 pm
i just stumbled upon your site and found it informative and helpful.a friend brought a compaq c500 laptop to us for repair, the problem is the white,moving lines which is about 1 centimeter thick.i dont know if the word “fuzzy” is a right adjective for it(sorry for im not a native english speaker).but when i disassembled the unit and reseated the display cable, the display was divided or tiled into 4 parts and when i tried reseating it again the display was totally lost(display on an external monitor is fine).further reseating didnt solve the problem and i am thinking that it might be related to the inverter or the display cable.any ideas?thank you in advance
April 15th, 2009 at 8:11 pm
karl dela cruz novoselic,
I think there is a problem with the LCD screen. With a bad cable you can get distortion on the screen but it would not divide the screen into 4 images.
When inverter fails, you still should be able to see a very faint image on the screen. Can you?
April 16th, 2009 at 6:30 am
Hey Repairman,
First thanks for your help, this site is great!
I got the inverter board in and replaced it and now the screen doesn’t come on at all. I can still see a faint image if I shine a flashlight at the screen though.
What should I do? Try to replace the bulb next?
I also tried putting the old inverter board back in and it does the same thing, doesn’t light up at all. Before I replaced it, it would come on for about 10-30 seconds and shut off. The screen also had a reddish glow to it.
Thanks in advance!
Justin
April 16th, 2009 at 1:11 pm
Justin Lancaster,
Hard to tell why it’s doing that. It’s possible you damaged the old inverter while replacing it with a new one. I cannot tell without testing your laptop with a KNOWN good inverter. Also, it’s possible that finally your backlight failed.
If the screen has reddish glow, most likely it’s related to a failing backlight lamp.
April 17th, 2009 at 11:57 am
First, congratulations for the site. I found some very valuable information.
I have a compaq evo n800c with a strange problem. The display (LCD) activates only one colum every 2 colums (consecutive colums, if “1″ is on and “O” off, it looks like 1010101010101010). Overall it looks like a loss in resolution. It is independent of the resolution selected for the video. I have dismounted the screen and (while powered on) disconnected the LCD. The result was a perfect white screen.
When connected to an extenal monitor, it works fine.
Can you help me identify the source of the problem ?
Thank you in advance.
April 17th, 2009 at 12:36 pm
Guillermo,
OK, let’s go through your problem step by step.
1. The external monitor works fine and the image on the external monitor is displayed properly. That tells me the motherboard and video card works properly.
2. When you unplug the video cable from the LCD screen it turns completely white. It’s normal. The screen is bright and that means the inverter board and backlight work properly.
3. I don’t think that your problem is related to the LCD cable. From my experience, LCD cables do not fail like that. When the cable fails, the whole image gets garbled or the screen doesn’t turn on at all.
I think your problem is related to the LCD screen.
April 19th, 2009 at 4:45 pm
thanks for the reply.i cant see any display on the screen even when i used a flash light to illuminate it so probably the lcd inverter is not defective. what can you suggest for me to replace first,is it the lcd, the display cable, or better to change them both?by the way i tried looking for a part number on the lcd and the display cable but i couldnt find one.any suggestions as to how i could find the exact parts?
April 21st, 2009 at 9:45 am
Hey repairman,
I have a laptop where the screen comes on for 1-5 seconds after boot and has a red tint to it. Have you ever seen the reddish tint caused by an inverter or is it always the backlight? Second, I’m debating whether to get the light or the whole screen. I had a customer get an lcd screen from ebay before and it had a horribly obvious bright pixel. Do you have a vendor you like that sells higer quality screens and parts and are there any that I definitely shouldn’t use? The screens on ebay for this Toshiba a135 go for around $60 and it would be easier than replacing the lamp, but the customer probably won’t be happy if the screen is defective. Also, if I do get the whole lcd and it is defective can I at least use its lamp?
April 21st, 2009 at 10:07 am
karl dela cruz novaselic,
Yep, your description in the previous comment doesn’t sound like a problem with the inverter.
It’s up to you.
But in my opinion you have a problem with the LCD. I could be wrong.
You can search for the whole display assembly (LCD screen, inverter, cable, plastic covers, etc…) If you can find one, you simply unplug the old display assembly and install a new one.
Do you have a white sticker glued to the video cable somewhere close to the connector which plugs into the system board? HP usually places the part number on that sticker. Look for the SPS number. If you can find it, most likely it’s the part number for the whole display assembly. Google the part number to make sure what it is.
April 21st, 2009 at 10:27 am
Mark,
From my experience this is a problem with the backlight lamp.
Can he return the screen for an exchange? There are a lot of good sellers on eBay.
I would definitely replace the whole screen. It’s cheap. Replacing the backlight lamp is very labor intensive. You can put a few hours into the repair and there is no guaranty it will work. I can replace the backlight lamp for fun or for my own screen but I never offer this repair to my customers. It takes too much time.
Just explain to the customer that replacing the whole screen is way cheaper.
It depends on what is defective. If it has a bad controller board (image is missing, garbled, has vertical lines) but lights up, it means the backlight lamp works properly and you can use it for another screen or as a test equipment.
April 24th, 2009 at 7:07 am
I have just checked my laptop with external monitor and its working fine. Now from above descriptions about LCD lamp and inverter…i am highly confused and not able to decide whether the problem is in lights or inverter. Still….while turning on the system my computer starts with florescent green color earlier it used to be blue and black)screen.I can see these green florescent tints on the desktop screen too. pink tints are also there
April 27th, 2009 at 2:33 am
Guys,
replaced the inverter board without taking out the battery first – now pc wont power on at all.
Any ideas?
April 27th, 2009 at 7:16 am
Kevin,
Turn off the laptop, remove the AC adapter and remove the battery. Wait for a few minutes, plug in the AC adapter and try turning it on.
April 28th, 2009 at 12:44 pm
shilp,
If the laptop screen lights up and you can see an image (even if it’s garbled), your inverter and backlight work properly. When inverter or backlight lamp fail, the screen is completely dark.
So, you are getting some green tint on both internal and external screens? That sounds like a problem with the video card. It’s very likely that your internal LCD screen doesn’t work because of a problem with the video card.
April 30th, 2009 at 6:29 pm
Been searching and haven’t found a symptom close to mine. I am working on a Dell Inspiron 6000. It’s first problem was a black horizontal line covering the 1/3 bottom part of the screen. Picture was fine on top. External monitor worked great. So I changed the screen. Now, at power on, the screen is fuzzy multi-color can’t see bios startup. Can see desktop but unable to read letters, very fuzzy and graphics look worse than safe mode. Now if I restart the computer, the screen goes to normal. I noticed that the inverter shows compatible p/n, and the screen I used to replace is not listed. Could that be the problem? The replacement screen p/n is LTD154EX0V.
May 1st, 2009 at 1:51 pm
Hi
I have a hp pavillion dv2275ea laptop I dropped the laptop and the screen cracked so I replaced the screen with a new one and its very dim I replaced the screen with the cracked screen again and its also dim should I replace the inverter with a new one and what could hace caused the inverter to go bad static from my fingers while I replaced the screen?
May 1st, 2009 at 1:59 pm
Hello
I have a hp pavillion dv2275ea laptop I dropped the laptop and the screen cracked so I replaced the screen with a new one and it is very dim, I replaced the laptop with the old cracked screen again and its also dim does this mean that i should replace the inverter with a new one? and what could hace caused the inverter to go bad static from my fingers while I replaced the screen because i changed the screen while it was all powered up or do i need to change any settings as laptop was connected to external monitor for a week or so?
May 3rd, 2009 at 5:08 am
Hey Repair Man..
I have a HP-Compaq NC2400 in which the screen shows color although with red tint for about 5-10 seconds, afterward, it turns dark although everything still work, internet, et cetera, all still working. The same thing happen every time I restart my laptop.
I’ve read your post and the comments here in general and so I just want to confirm. At first I thought it was my LCD inverter that went wrong, but now I started to get confused whether it is my backlight that is wrong. So, which is it?
Thanks in advance…
May 3rd, 2009 at 10:52 am
Nico,
That could be poor connection between the video cable and motherboard, defective video cable or bad LCD screen.
Open up the display panel so you can access the video cable behind the screen. Now turn on the laptop and when you get image on the screen carefully touch/move the video cable. Does it make any difference?
I don’t think that your problem is related to the inverter board. In your case the screen lights up and is bright. That means the backligth lamp and ivnerter work properly. Nope, it’s not the inverter problem.
Here are some troubleshooting tips:
1. Check connection between the video cable and motherboard. Make sure it’s plugged in correctly. Reconnect the cable just in case and test the laptop again.
2. Try connecting the old LCD screen back to the laptop. If you still experience the same problem with the old screen (the bottom part doesn’t work) but your new screen has a different problem (fuzzy image), the new screen is either incompatible with the laptop or is bad. Did you try connecting the old screen?
3. Try replacing the video cable.
May 3rd, 2009 at 11:10 am
nick singh,
First of all, make sure the video cable is properly connected to LCD screen, inverter board, motherboard. It’s possible that you accidentally pulled the cable while replacing the screen. Try reseating the cable.
Yes, it’s possible.
1. Check the connection.
2. Replace the inverter.
May 4th, 2009 at 5:43 pm
Thanks! It was the lcd screen. Apparently the replacement screen was also defective. Glad I stumbled upon this site. Great information.
May 4th, 2009 at 8:24 pm
Linda,
Your description sounds like a problem with the backlight lamp inside the LCD screen.
From my experience, the red tint on startup can be cause by a faulty backlight lamp. Inverters do not fail this way.
May 7th, 2009 at 6:22 am
I have a Dell Inspiron e1505… has worked fine with NO faults until this morning. I get up and the screen is pitch black. I restart the computer and I will get about 10-15 seconds of full color then straight to black. Several hours later I notice that I’m getting a “shadow” of my screen showing in the background when I was thinking it was black.
From reading a handful of pages this sounds like an inverter – am I correct in thinking so? I am able to get little flickers of full color (1-2 seconds tops) if I close the lid then re-open the lid.
I’d love to be able to do the repair myself and save a few $$s but I’ve never worked on my laptop and I have all the files for my company on it. Unfortunately I haven’t backed it up in a few weeks either. I can tell everything is there, but I’m worried that if I tried to do the repair myself I’d mess it up. Is this the sort of repair that I can entrust to Geek Squad? Also, would I be better off ordering an inverter myself or just buying it through them?
May 7th, 2009 at 8:25 am
Elissa,
It’s either a bad inverter board (which is most likely) or faulty backlight lamp (which is less likely). If you have no test equipment and have to guess, i would definitely try replacing the inverter board first.
Here are instructions for taking apart the display panel in a Dell Inspiron 6400/E1505 laptop.
You don’t have to remove the whole display panel, it may stay attached to the laptop. Go straight to the Removing the Display Bezel instructions.
As you see, the inverter board is attached to the bottom of the LCD screen. You’ll have to figure out how to remove the inverter and replace it with a new one.
Replacing the inverter board shouldn’t mess any data on the hard drive but if you don’t feel comfortable doing that, take the laptop to a repair shop.
By the way, you can remove the hard drive from the laptop and install it into an external USB enclosure ($20-30 in a local computer store). After that you connect this enclosure to another working computer and access your data.
May 7th, 2009 at 8:34 am
Repair Man,
Thanks for the info! I took the information about suspecting an inverter or backlight to the computer shop that built my first computer… I’m taking it in tomorrow after I dump my files tonight (just in case it’s the motherboard and I decide to not fix it).
Thanks for the insight though. I was definitely flipping out this morning and didn’t realize quite how common this sort of problem is with laptops.
May 8th, 2009 at 8:40 am
thank you!
it was the inverter. i never repaired any laptop but replacing the inverter was easy. i found instruction for my dell inspiron in the service manual from dell website. found new inverter on ebay for $25 and replaced myself. saved me $100.
May 8th, 2009 at 9:05 am
tom,
I found that Dell website is a very valuable source for all DIY-ers. They have very good laptop disassembly instructions and I use it all the time. I wish all laptop manufacturers would be the same.
May 13th, 2009 at 1:26 pm
I took apart and old laptop, put it back and the screen is now dim all the time. Besides that everything is fine. Could it be the inverter? Works fine with an external VGA connected monitor.
It’s a Dell Latitude C family.
May 13th, 2009 at 1:36 pm
Stan,
Could be connection related issue. Make sure the video cable is properly connected to LCD, motherboard, inverter board. Try reconnecting the cable.
May 17th, 2009 at 10:08 am
Please send “taking apart the display panel” for my Dell Inspiron 1200 laptop. I am going to try to replace the inverter. Hopefully, this will correct the problem. After reading all the comments posted here, I believe this is my problem!
May 18th, 2009 at 8:04 am
Shelley,
You’ll find the display disassembly instructions in the service manual, here’s the link.
You don’t have to separate the display panel from the computer base. You can remove the bezel while the display is still attached to the base.
May 20th, 2009 at 5:59 am
Hi, my Toshiba Satellite M105-S3041 has developed an issue where the screen dims when the screen is moved up and down or due to some vibration, there is also a buzzing noise when this happens. I have to move the screen around normally to correct it. Does this sound like I need to replace the screen inverter? or could it be the video cable that is faulty? or something else? It’s normally fine when there is no physical movement. Please also recommend a site to order the part from. Thanks!
May 26th, 2009 at 8:49 pm
Mark,
That could be:
1. Loose connection between the video cable and LCD screen or inverter board. Try reconnecting the cable first.
2. Bad video cable.
I don’t think that your problem is related to the inverter because you can fix it by moving the display.
June 2nd, 2009 at 6:51 pm
Hello.
I believe my dv9000 is experiencing the issues described above; the only issue that has me wondering whether or it is the board itself is that when I plug an external display, I’m only able to view a broken image by booting into Safe Mode. The image has broken lines and a bit distorted. Any guidance on what may be the root cause? In advance, I appreciate your help.
June 3rd, 2009 at 2:12 pm
Hi, I have an issue with my Dell e6400. I dropped it, the screen broke with only half of it still displaying properly. I bought a new one from LCDWORLD on ebay and it works great, IF I’m plugged into AC. Trying to start up the laptop on battery will result in a blank screen while starting up on AC works fine. After the laptop is started up, I can disconnect the AC power and the screen will stay on. Any clues? Could it be the inverter? Why does the screen stay on even after unplugging from the wall?
Thanks, Franco
June 4th, 2009 at 6:43 am
My lcd screen goes black on AC but works fine on battery, external monitor works ok either way, screen shows desktop when black on battery when shine light on it. Inverter,power supply or what is it??
Robert
June 4th, 2009 at 7:07 am
Sorry I got cut off (hit enter instead of backspace) while editing, its a HP DV6810US and running Ubuntu 9.04 linux ,,and I have checked all Power settings HELP! I do have a new inverter coming in soon, what does it sound like to you? I keep thinking weak inverter or weak power supply, I looked at the inverter and it looks like the clear plastic over the copper coil is dis-colored brownish like maybe from heat, are these normally dis-colored or remain clear with normal use? thanks Robert
June 4th, 2009 at 7:25 pm
I am having a similer problem with my Gateway ma2 6021gz, When I power on the system the onboard lcd lights up gray and has no picture what so ever, an external monitor works fine, is this an inverter, lcd, MB, or video cable broblem??
Thanks in advance, Chris
June 5th, 2009 at 1:05 pm
Well the new display inverter fixed it all,works fine all the way!
Robert
June 6th, 2009 at 11:17 am
John V,
Which one? No backlight?
If you get a garbled image on the external monitor, most likely your problem is related to the video card. The screen inverter board cannot affect image on the external monitor at all.
Again, if you are talking about the image on the external monitor, it sounds like a problem with the video card.
Do you know that HP fixes some out-of-warranty dv2000/dv6000/dv9000 notebooks at no charge? Here’s more information about HP warranty extension program. Maybe your dv6000 qualifies for that repair.
June 6th, 2009 at 11:36 am
Franco,
Did you replace just the LCD screen or the new screen came with the inverter board?
Have you tried connecting the old (broken) screen back to the laptop and test if it lights up properly from the AC adapter and battery?
June 6th, 2009 at 12:24 pm
Chris,
The LCD lights up so it’s not the inverter. The external monitor works fine so the video card and motherboard work properly.
I think it’s either bad LCD cable or bad video cable.
June 7th, 2009 at 10:58 am
Hi
I have a problem with an lcd screen on a laptop.
The screen has paler areas arond the bottom edge and right hand side but the picture is all there, just paler.
Do you think this is an inverter problem or is the screen on it’s way out?
June 7th, 2009 at 11:10 am
Kevin S,
It’s not related to the inverter board, that’s for sure. The LCD screen is still bright and you can see the image, so the inverter works properly.
Something is wrong with the LCD screen.
June 7th, 2009 at 5:12 pm
Hi,
I have a Toshiba Satellite M105 S3004 laptop with a 14 inch LCD Display. The screen in my laptop is very dark but i can see the images still being there. However, if i put the screen down for standby and open it back up, the screen becomes brightes for a few seconds and gets dark again. Is this a problem with the backlight or the inverter or any other component.
Additionally, when it does light up, the right side of the screen is brighter than the left side. Is this all becasue of the same problem? Will really appreciate your help.
June 7th, 2009 at 5:46 pm
John,
It’s hard to tell which one is failing. It’s either bad inverter or backlight. Both parts have very similar failure symptoms. In order to find out which one is causing the problem you’ll have to replace the inverter board or test the laptop with a known good backlight lamp.
Now that sounds more like the backlight lamp failure.
June 7th, 2009 at 11:49 pm
Hi.
I’ve changed a broken screen on an HP Pavilion dv5000, first start worked really fine, all light and brite, put all together again and now almost no light, just very dark.
tried on external screen, works fine.
tried another inverter, same dark screen
tried another screen, same dark screen
took some more apart and checked the screen cable were seated at board, same dark screen.
Now I’m out of ideas!!
Thanks for your help
Bobby
June 11th, 2009 at 5:39 am
Hello, I am actually having the exact same problems as Bobby. What could this be? I replaced the screen and on the first couple starts, it worked perfectly normal. Everything wasn’t put back together so I finished up the install, and all of a sudden its just very dark. External monitor works normal. Any thoughts on our problems? Could it be the video cable or the motherboard?
June 18th, 2009 at 6:00 am
Hi.I have a toshiba laptop EL10-142 working fine except there is no backlight.It works on a external monitor when first turned on but then it returns to the dark laptop screen.I have bought two replacement inverters from ebay but still no joy.When i test them with a multimeter they all have 14.75 dc volts going in at the top pin one end but no ac at the other.I used the laptop as an earth and probed both pins inside.I also probed both pins at the same time as i am not sure of the correct way to test ac current.Should there be power at the backlight end? if so do you think that both replacements could be faulty? Please help.Thanks Pam.
June 19th, 2009 at 11:35 am
Hello. My wife stored a bottle of water with her laptop in the carring case. Unbeknownst to her, the cap had fallen of the water bottle and the laptop had been sitting in about a 1/4″ of water for about an hour. The laptop was in standby and the backside (where the screen connects to the laptop) was the only part of the computer immersed in the water.
After letting it dry thoroughly, we tested the computer. The laptop turns on and works fine with an external monitor. However, the screen remains extremely dark all the time with only a very dim image outline (can be seen with a flashlight). Do you think it is the inverter, backlight, or both. Thank you for any help you can provide.
June 19th, 2009 at 12:08 pm
pam,
Looks like the power gets to to inverter and the voltage is about right. You cannot test voltage on the other end with a multimeter.
It’s possible but not very likely.
I think you have a problem with the backlight lamp inside the LCD screen. You can test the backlight using the method I linked to in the comment 107.
July 10th, 2009 at 9:26 am
Hello, i have same problem. Change broken screen, tried on external screen, works fine,tried another inverter, same dark screen,tried another screen, same dark screen. Maybe You resolve this problem?
Thanks for your help
Viktoras
Bobby Says:
June 7th, 2009 at 11:49 pm
Hi.
I’ve changed a broken screen on an HP Pavilion dv5000, first start worked really fine, all light and brite, put all together again and now almost no light, just very dark.
tried on external screen, works fine.
tried another inverter, same dark screen
tried another screen, same dark screen
took some more apart and checked the screen cable were seated at board, same dark screen.
Now I’m out of ideas!!
Thanks for your help
Bobby
July 10th, 2009 at 10:39 am
Victoras,
Did your broken screen light up at all?
If it did, try connecting the broken screen again. If the broken screen still lights up but the new one doesn’t, it’s possible there is a problem with the new screen.
July 11th, 2009 at 8:11 pm
Hey Repair Man,
When I open my DV9740US HP Pavillion all the way, the black areas become red and dotty, but when I pull the screen towards me (to about where its 70 degrees open) – the screen goes back to normal. Does this sound like a loose connection, or some bigger hardware issue? Not having any other noticeable problems. I’m a little nervous about making the repair, but don’t have any other options (no $$$ and I’m a college student).
July 16th, 2009 at 9:06 pm
William,
First of all test you laptop with an external monitor. Do you see same problem on the external monitor when the laptop display is open all the way? If you do, there could be a problem with the video card.
If the problem appears only on the laptop screen and external video is fine, most likely it’s either cable related problem or bad LCD. You can try reconnecting the cable.
July 23rd, 2009 at 3:26 am
I have an Acer 4710z.
The display shows only lines and a pale gray colour, no image. The inverter is working fine, since with the signal cable unplugged the screen lights up white. On plugging the signal cable the lines return. I am not sure if it is the cable or the LCD to blame.
Any idea?
July 25th, 2009 at 10:28 am
I have a Dell Vostro 1400.
The display is just black. It does not work with a external monitor, the same results black screen.
I can see the Dell logo when the laptop first boots. I can run the diagnostics, which detects no problems the video test is fine as well. I can see all the patterns. I can go into the Bios without any problems. After the Dell logo comes up when I first boot the computer it goes black. No beeps or anything. Could this be a inverter or back light problem?
Thanks
July 25th, 2009 at 8:42 pm
htnakirs,
That’s right. If the screen lights up there is nothing wrong with the inverter board.
Test the laptop with an external monitor. Can you get video on the external monitor?
If you get the same bad image on both screens, there is a problem with the motherboard. Test your laptop with an external monitor first.
July 25th, 2009 at 9:17 pm
Mike,
Can you boot in Safe mode? When Dell logo appears on the screen, press F8 and select Safe Mode. Will it boot this way?
August 9th, 2009 at 8:32 am
I have a presario c700. my screen has a dim image of my backround in the back but the backlight is not working. it came on for about 5 seconds once but has not worked since . i connected it to aan external display and it worked ok. can anyone help???
August 11th, 2009 at 7:54 pm
Thanks, very good information.
August 13th, 2009 at 11:23 am
Alan,
Could be faulty inverter board or backlight lamp. You cannot tell without testing the laptop with a known good inverter or backlightl lamp.
If you have to guess, try replacing the inverter board first. You have a very good chance to fix the problem.
August 17th, 2009 at 12:34 pm
I have a Pavilion DV9700 with a problem of the screen going black after random periods of time and not coming back via the mousepad as it does with display timeouts. Laptop is still running and restart or going to sleep (via start/u/enter) and waking up bring the screen back. All power settings set to never (this is plugged in). I do notice failure takes much longer if the screen is dimmer. Can’t try external monitor until I get home from this vacation. Watching a movie seems to make it occur faster. Could this still be an inverter problem, or is it the backlight overheating? Whenever I have a picture, it’s perfect. With backlight a little dim, I can go for hours, sometimes days, doing normal computer stuff (not movies) without a failure.
August 17th, 2009 at 12:52 pm
David Dell,
Could be either one. Cannot tell until you test the laptop with a known good inverter or backligth. Replace the inverter first and if no help, deal with the backlight lamp. Replacing the inverter board is not difficult. Here are instructions for a HP Pavilion dv9000 notebook.
August 28th, 2009 at 4:53 am
hi how do i remove the back light on prsario c500
August 28th, 2009 at 10:31 am
george tippet,
Do you mean the backlight lamp? It’s not easy even for experienced technicians.
The backlight lamp is mounted INSIDE the LCD screen.
In order to remove the backligth, you’ll have to go through the following steps:
1. Disassemble the display panel and remove the LCD screen. Here’s an example for a Compaq Presario F700 notebook, could be similar to your laptop.
2. Disassemble the LCD screen and access the backlight lamp. Here’s an example of removing the backlight lamp.
If you think the backlight is bad, I would suggest replacing the whole LCD screen.
September 9th, 2009 at 3:46 am
Thank you very much for the information.
I came across your site while searching for some answers. I recently replaced my laptop’s LCD and it is working fine. The connector to the inverter for the new LCD was not the same as the old one. So we had to cut the old cable and attach it to the new one to connected. Now I am a bit worried because the screen is a bit brighter than the old one. Could I have made an error in connecting a non-compatible LCD?
September 9th, 2009 at 7:02 am
Tommy,
It’s possible that the backlight lamp inside the new LCD requires a different less powerful inverter board.
Try reducing the screen brightness a little bit.
September 17th, 2009 at 9:34 am
Hi, coffee was spilled on the keyboard of my Dell XPS M1210 laptop. Now it seems to have symptoms of an inverter failure; I’ve verified that it works fine with an external monitor, no pinkish hue, only a very faint display always. This model seems to have a magnetic lid close detector rather than a button.
I’ve bought a used inverter off ebay but same result. I will send it back for another to rule out if it’s a bad one. Any other considerations?
Did the coffee spill cause the inverter to fry most likely and this is common in your experience?
Thanks,
September 22nd, 2009 at 7:23 am
I have a Dell Inspiron e1505 laptop.
I am trying to determine if it is the inverter or the backlight that needs replacing. Maybe you can tell if I provide more detail on the symptoms? The image degraded over a period of time: for a few weeks, the image got harder to see in the left bottom left corner. A couple of times, the screen went black but then it worked again when I tried later. Then one day while the system was on, it made a sound, like a zzzzzt and then a pop. The screen went black and hasn’t worked since. Except that it does show the power-on screen and I can see the image on the display with a flashlight. Also, an external monitor works fine. I did notice will using it with an external display a buzzing sound coming from the system but that has stopped now.
September 22nd, 2009 at 11:31 am
Ed,
Most likely your problem is not related to the inverter board. To me it sounds like a problem with the motherboard.
Apparenlty, the liquid went down to the motherboard and damged it.
You’ll have to remove the top cover and take a closer look at the motherboard. If you see corrosion or any other sign of liquid damage, you’ll have to replace the motherboard.
September 22nd, 2009 at 11:46 am
Jodi MacDonald,
This part of your description sounds like a problem with the backlight lamp but also could be related to the inverter, maybe it’s not providing enough power for the lamp.
This part sounds like a problem with the inverter board. Last week I repaired one laptop with exactly the same problem description (it made a sound, like a zzzzzt and then a pop). I replaced the inverter board and it fixed it.
First of all, I would try replacing the inverter. It shouldn’t be very expensive. If no help, you’ll need a new LCD screen.
September 22nd, 2009 at 12:18 pm
Thanks Repair Man,
Though I don’t see any signs at all of corrosion it seems there’s no coincidence this issue happened after the spill. Just that the laptop works fine except for the LCD, so I was hoping for a fix based on what I’ve read here. Worst case I guess will be to use it with an external monitor here on out.
If you have any other ideas please let me know. Another inverter is in the mail to try. I was considering getting another LCD to try but not so much now since your response.
Thanks again,
September 22nd, 2009 at 8:42 pm
Hello, I’m just asking for some help with my Sony VAIO laptop.There seems to be something wrong with the screen, when I turned it on I wasn’t taken to the startup screen. Instead the screen shows only a portion of the windows telling something with an error.All over the screen, there’s a black leaf shaped thing connected with black lines. A large part of the lower screen is white, which is sepearated by black lines with the others (the left side of the screen is gray and a small portion where you can see the desktop cursor can be located at the top.)
Does anyone know about this?
September 22nd, 2009 at 9:47 pm
Ed I have the same problem with my old laptop but the difference it’s a HP Pavilion Dv9000s. I’ve been trying to decide if I need a new inverter or a blacklight. I spilled liquid on it and it works perfectly fine on an external monitor. If The spilled liquid went and damaged my motherboard, would my computer even work?
The screen comes on but is very dim.
September 22nd, 2009 at 10:14 pm
Ed,
Here’s a quote from your description.
It sounds like the failure occurred right after the spill. Also, you said that coffee was spilled on the keyboard, not on the display, so it’s not related to the inverter/backligth lamp UNLESS the coffee shorted something on the motherboard and killed the inverter or backlight.
Here’s how you can test if the problem is related to the backlight lamp without buying a new LCD. You’ll have to buy a new backlight lamp though.
September 22nd, 2009 at 10:23 pm
Kaye,
Sounds like the LCD screen is your laptop is cracked. When you have a broken screen the only way to fix it would be installing a new LCD screen.
You’ll have to disassemble the display panel (remove display bezel), unplug the cracked LCD screen from the video cable and inverter and replace it with a new screen.
Not difficult but an expensive repair.
September 22nd, 2009 at 10:27 pm
Krys,
Here’s the cheapest way to test the laptop and find out if your problem is related to the inverter/backlight/motherboard.
1. Buy a new inverter. Test. If no help, go to the step 2.
2. Buy a new backlight lamp (link in comment 137). Test. If no help, most likely it’s the motherboard failure.
Liquid spills are very unpredictable. Even a small drop of liquid on the motherboard can fry the entire system.
September 24th, 2009 at 3:33 pm
hello, I hope you can help. My daughter spilled tea on her Mac laptop yesterday. I let it dry upside down for a day and removed the battery. It powers up and it looks like everything is working except the screen is dark. We can make out all the images, but too dark to work on. What is your best guess and what do you think I should do at this point.
Thank you in advance.
Tom
September 24th, 2009 at 6:10 pm
Tom,
Did she spill it on the keyboard or display?
If she spilled it on the keyboard, most likely the tea wend down to the motherboard and damaged it.
Let it dry for some more time. Do not forget to remove the battery. Who knows, it might start properly in a few days.
September 28th, 2009 at 8:38 am
Thanks Repair Man. I will get a LCD lamp (with a small plug in my case) from ebay to test with per your recommendation. I see some there for $20 with plug.
Also, I will test with multimeter, unless you think power is not likely the issue with my description.
Tom, per Repair Man verify if you can plug in an external monitor and get a normal picture. That will confirm if your video card is working. In my case it works fine and the PC seems normal. I’ve tried an inverter so my next step is to test the backlight. If it works, I’ll buy a new LCD screen for around $120.
Thanks again,
September 29th, 2009 at 2:34 am
hi..i found more intresting information about this part of a laptop.
however, one thing i want to know – when this “Screen inverter board” works normally, does it rise temperature, cause the part in my laptop under the “HP” logo on screen gets warm, and, of course, it rise tempereture of lower part of the display.
September 29th, 2009 at 8:34 am
or maybe this is a reason of a backlight lamp, cause, as i realized, its located in the bottom of the screen?.
October 1st, 2009 at 4:51 am
Hey Repairman,
I have an HP DV5000, sometimes when I move the screen, either to close it or to adjust it’s position, the screen flickers. It usually only happens if I grab the sides of the screen. I’m not sure what this could be, I tried changing the inverter, but apparently the one I ordered online is the wrong one because the backlight would come on for about a second then the screen would go dark, I put the old one back in and it works fine, but I still have the flickering problem. Before I go crazy trying to find the correct inverter for this machine, do you have any other suggestions?
October 1st, 2009 at 12:15 pm
Dan,
I don’t think that your problem is related to the inverter board because it flickers only when you move or adjust the display. With a failed inverter the screen would be black all the time.
It sounds more like a connection related issue.
Here’s what you can try:
1. Try reconnecting video cable on the back of the LCD screen. Maybe the cable doesn’t make good connection with the screen.
2. Try replacing the video cable. It’s possible you have a short inside the cable.
3. Could be LCD screen failure.
October 1st, 2009 at 12:45 pm
zigymantas,
There is a backlight lamp mounted inside the LCD screen, it’s on the bottom of the screen. When the backlight lamp is on, it generates heat.
It’s normal when the bottom part of the display panel is warm. It’s getting warm because of working backlight.
By the way, the inverter board also generates some heat when it’s on.
October 2nd, 2009 at 12:17 pm
Hello,
A few days ago, without any warning sign, after almost two years of trouble-free operation, my laptop screen started to flicker until it finally settled to a gray color, with barely visible vertical stripes.
I stopped it forcefully (by pressing the power button for a few seconds). After restart the same gray screen appeared right from the beginning. When I left it turned on, the screen gradually changed color to a blue-green shade (resembling the one from Windows 7’s logon screen).
Later that day, when I restarted the laptop, all went ok, at least for a while. After some two hours of operation, the flicker happened again and all the symptoms were back.
I plugged in my desktop’s monitor and after displaying the Win7 bootscreen it returned a BSOD (nvlddmkm.sys). Afterward I could get it to work somewhat reliably only in safe mode with networking support.
Before any subsequent start of the laptop, I first tryied using its own display. On several occasions it worked normally and for quite a few hours before it freezed.
I also started to get some WHEA errors in the Event log (WHEA-Logger EventID 19 Warning A corrected hardware error has occurred, WHEA-Logger EventID 18 Error A fatal hardware error has occurred.)
I then tryied uninstalling/reinstalling the drivers for the chipset (nforce 7000M) and video adapter (nVidia 8600M GS), all without any positive result.
I also suspect these problems might be related to heating issues (the video chip is rated at ~70-80 C).
I took a look inside the laptop’s display and there were no apparent signs of damage to any of the components.
Now, I can use it only connected to the external monitor and only in safe mode. If I try to use the laptop’s own screen, it only displays the vertical gray lines that eventually turn blueish after leaving it on for a couple of minutes.
My biggest concern is whether to buy a new Acer screen or a new laptop alltogether. I thought that by describing these details to you, you might have some clues in order to pin down the issue and make a decision.
I’m sorry for this long message. I’d appreciate your help.
Thank you.
My specs:
Acer Aspire 5520G
AMD Turion 64 X2 TL-58, 1900 MHz
nVidia nForce 7000M-610M (southbridge), AMD Hammer DDR 2 IMC (northbridge)
2048 MB RAM
nVidia GeForce 8600M GS, 512 MB GDDR2
Acer CrystalBrite 15.4″ LCD (LG Philips), WXGA
Windows 7 Ultimate 64bit (worked fine for around a month before this whole thing happened)
October 3rd, 2009 at 10:16 pm
I have a problem with a Dell Vostro 1400 laptop.
Recently, upon waking from standby, the bottom 2/3’s of the LCD is covered by close-together horizontal lines. This problem is resolved by a shut down and restart. However, it recurs when the unit goes into standby again.
Easy enough not to allow the machine to go into standby, but concerned this is an early indicator of something worse component wise starting to fail.
Did not know if this was an indication of the inverter starting to go, or if the standby problem indicates something more related to the video card or some other problem…
Any suggestions on where to start/test?
Thanks.
October 5th, 2009 at 11:29 am
Oh – one more thing RE: intermittent LCD problem.
When this problem was occurring, I did hook up an external monitor and that display was fine, no problem. Happy enough to replace the LCD and/or inverter, but was curious if the intermittent nature was an indication of some other problem which replacing these would not remedy.
Thanks.
October 7th, 2009 at 12:46 am
Update @comment #148:
In the last days I didn’t even bother to try to use the laptop’s display anymore. I struggled with the external monitor, in safe mode. I then observed some vertical blueish lines in a regular pattern (about an inch between each group of lines).
I wanted to test this on another external display. It reproduced. Then I booted an Ubuntu from an USB stick. The line pattern persisted. I thought that the problem was with the video card.
But something happened in this stupid saga. Last night I connected again the desktop monitor to the laptop and booted from an Ubuntu USB stick. It didn’t show the line pattern. Then I bootted from the HDD (Win7) in normal mode (previously, it worked in safe mode only). Again, surprise, it worked. Then, I disconnected the external display and tryied to use the laptop’s display. It worked again!
Right now, I’m writing this from my laptop, using its display. It behaves like nothing happened in this last week. Well, almost – the same freaking WHEA errors continue to appear (WHEA-Logger EventID 19, 18). I’m expecting a failure anytime.
Anyway, it seems I’ll eventually have to buy another laptop (this time it won’t be Acer/AMD/nVidia; I’m trying my luck with an Asus/Intel/Ati). Thanks for bothering with my messages.
October 7th, 2009 at 1:20 pm
This post just saved my boyfriend’s dad $400.00!!!! The screen display was really dim but the computer booted up fine. So it turned out that the LCD battery back up thing was partially unplugged from the inverter. and all I had to do was open it up. Thank you so freakin much!
October 10th, 2009 at 10:44 am
Hally,
I really doubt that your problem is related to the LCD screen.
In your comment you said:
This sounds like a problem with the video card.
In a case of LCD screen failure, you still should be able to use the laptop with an external monitor with normal resolution, but you can use it only in Safe mode when only basic video driver is loaded.
I’m not familiar with your model. If the video card is integrated into the motherboard, you’ll have to replace the whole motherboard. If the video card is a discrete module, you can replace just the video card.
October 10th, 2009 at 11:25 am
Mike,
First of all, your problem is not related to the inverter board. When the bottom 2/3s’ of the screen fails, you still can see the rest of the screen. That means the inverter powers up the backlight and works properly.
Your problem could be related to:
1. Loose connection between the video cable and LCD screen. You can remove the keyboard bezel and try reconnecting the video cable. Here’s a guide for Vostro 1510 notebook, could be similar to yours. Take a look at the step 7. The video cable connector in Vostro 1510 is located close to the left hinge.
2. Start the laptop while the keyboard bezel is removed. Now carefully move the video cable without moving/touching the screen. Does it affect video on the screen. If the video changes when you move the video cable, it’s possible that you have a bad cable. Apparently there is short inside the cable. Try replacing the cable.
3. Turn on the laptop and wait until video fails. Can you get it back to normal by moving the screen back and forth? Can you get it back to normal if you torque the screen a little bit? If yes, most likely you have a faulty LCD screen. You’ll have to replace the screen.
October 10th, 2009 at 11:27 am
Mike,
That means the motherboard and video card work properly.
Again, as I mentioned in my previous comment, it’s not related to the inverter.
Try reconnecting the cable first, could be just loose connection.
October 10th, 2009 at 1:39 pm
Hally,
I does sound like a problem with the video card.
You said the laptop works fine for now, but most likely it will fail in the future.
After you mentioned vertical blueish lines in a regular pattern on the external screen, I’m 99% positive that you have a faulty video card.
October 10th, 2009 at 1:40 pm
Julie,
Congratulations! I’m glad that my site helps people.
October 11th, 2009 at 11:44 am
I have a brand new high end Dell laptop funning Vista. I want to use an external 22″ monitor with it. When I plug in the monitor, the screen has a pink tint. I have tried everything but cannot do anything to make this go away. I plugged the monitor into a desktop (running XP) that I have and the screen looks fine. Any ideas???
Thanks in advance.
October 11th, 2009 at 12:09 pm
steven,
The video works fine on the external monitor, so there is nothing wrong with the laptop or software.
You are using different cables for the TV and external monitor, correct? I think the cable running from the laptop to the 22″ TV could be bad or not plugged correctly. Try reconnecting the cable and if it doesn’t help, try another cable.
October 11th, 2009 at 11:58 pm
Hey, I have an HP Pavillion dv6000 laptop and I had a screw fall out of the back of it and the screw was connected to the monitor. So I was moving the monitor around quite a bit to fix the screw. When I was moving it around the screen went almost completely black. So now I can see very faint images on the screen but they are almost invisible and almost completely black. I was wondering if you think this is the Blacklight lamp or the Inverter Board or possibly something else. My computer is no longer under warranty and it is also my work computer so I am freaking out and want to fix it myself and not tell my boss about the problem. Any help would be much appreciated!! Have a wonderful night!
October 12th, 2009 at 10:49 am
Repair Man, re: my M1210 w/ the coffee spill, I bought a new LCD lamp to test with per your recommendation. But, no diff connecting to 2 different inverters. Any final suggestions to try, like the LCD cable perhaps?
If not, I’ll decide to either replace the mobo or just try to use with an external monitor going forward.
Thanks again,
October 13th, 2009 at 7:59 pm
Ed,
Can you see any damage made by spilled coffee on the video cable?
If not, I really doubt that a new cable will make any difference.
If a new LCD lamp and inverters didn’t help to light up the LCD, most likely you have a problem with the motherboard.
October 13th, 2009 at 8:04 pm
Nikki,
What does it mean? How can you fix the screw by moving the monitor. It’s not clear.
I cannot tell what is wrong without looking at the laptop.
Could be bad connection between the video cable and inverter. Reseating the cable connection may help.
October 24th, 2009 at 12:21 pm
My Dell Inspiron E1505 laptop has been having a display problem: the screen is dark with barely visible images but it works fine with an external monitor. I commented about it on this site a few weeks ago and determined that my inverter needed replacing. I bought a replacement inverter online (not a genuine Dell part). It didn’t look exactly like the one in the latop, but it fit. Once it was installed, the display worked again. Yea! But after about 20 minutes, I noticed the screen looked pinkish: this had happened the first time the display failed. Then, without warning the screen went black and that was it. It functioned for maybe 1 hour befor ethis happended. The symptoms are the same as the first time: I can faintly see images on the display but the screen is not backlit. Is my laptop burning out inverters for some reason? Is there a remedy? Could it be because I didn’t use the precise Dell replacement part?
October 27th, 2009 at 8:23 am
Jodi,
Most likely it’s either bad inverter or backlight lamp failure.
I would suggest replacing it with the exact replacement part. I cannot tell if your new inverter works properly or not.
It’s likely that there is nothing wrong with the inverter board. Usually the screen looks pinkish when it has a faulty backlight lamp.
When the backlight fails, you have to replace the LCD screen. It’s very hard to replace the backlight lamp inside the screen though possible.
Take a look at this post. It explains how to test the inverter board without buying the entire LCD screen (you still have to buy a new backlight for test).
Again, you mentioned the pinkish screen and I think it’s related to the backlight lamp failure.
October 28th, 2009 at 5:51 pm
Repair Man
I have an HP ZE5478Cl with the hi res screen. It works sometimes, but will intermittently start flickering, and it looks like a tv with vertical hold problems, white bars flickering. Is that an inverter? it never goes dark. works fine with an external monitor too
thanks
October 29th, 2009 at 1:36 pm
Ron,
This doesn’t sound like inverter failure.
I think it could be:
1. Loose connection between the video cable and LCD screen/motherboard. Try reseating connections.
2. Bad video cable. Try replacing the cable.
3. Bad LCD screen. Try replacing the screen.
October 29th, 2009 at 4:50 pm
I have a HP DV6244. The screen flickers and dims on the left side only. The right side of the display is bright. The dimming is not black, but more like the display looks when you are running on battery. Fully visible, all the colors, just dimmed. the other half is fine (note that this is half divided vertically from top). Moving the lid sometimes makes the screen go normal, but this is not repeatable. I sent this machine into HP under warranty 2 yrs ago for same issue, and it was fixed then. It has reoccured.
Is this an inverter, cable, or (budget forbid) a backlight/screen?
October 29th, 2009 at 8:07 pm
Chip,
Do you remember what did they replaced last time?
It’s not the inverter or video cable failure.
Sounds like a failing backlight lamp inside the LCD screen. I think you’ll have to replace the screen.
October 30th, 2009 at 5:25 am
Repair man:
it was sent on Dec 21 2007, returned Jan 6, 2008. I assume that it is out of warranty, including the repair.
Is the backlight lamp replaceable, or do I need an entire screen for this model?
October 30th, 2009 at 3:46 pm
Hey,
About a week ago my laptop started giving me problems. My screen just went dark and before It went dark it use to have a little flickering. Than recently it just went completely dark, but I noticed that my battery light wasn’t showing up. If I plug it to ac power the light won’t even show that it’s charging. Before the screen went dark for like a month or two I noticed that if I run the laptop on it’s own battery it would say battery too low when it’s been on charge for like two days. I am confused if it’s just the battery that needs to be replaced for the inverter or backlight. How can I know for sure cuz my friend tried to use external monitor on it and nothing showed up on the external screen. Also the computer runs fine I can see that windows opened up and if I look close I see something in the background but the battery light won’t show up either. Hope u can help me to figure out if it’s battery or something else.
October 31st, 2009 at 3:29 pm
Does anybody know the pinout, and specs of this inverter board?
It came out of a toshiba satellite L45, is branded asus and has a part number listed as 08g23fj101c, revision 1.0. It has a 10 pin connector, with an unused pin on the far right.
November 1st, 2009 at 1:31 pm
Repair Man:
I commented on my HP DV-6244US earlier where I had a flicker problem that affected one half of my screen. Given I had little to lose, I took the bezel off my LCD, and probed the wires with the laptop on. As a result I found that the lead into the inverter was loose, and upon a bit wiggling, found it fixed the flicker and the screen returned to full brightness. I taped it in place with electrician’s tape and so far, is behaving properly.
November 3rd, 2009 at 8:26 am
Chip,
The backlight lamp is mounted inside the LCD screen. It’s very hard to replace the lamp because you have to disassemble the LCD. You can try replacing the lamp but only if you have nothing to lose, take a look at this guide: Replacing backlight lamp in a laptop computer. It’s very easy to damage the LCD screen while replacing the lamp.
It’s way easier to replace just the LCD screen. Here’s another guide for you: Replacing LCD screen in HP Pavilion dv6000.
These days new LCD screens are not expensive.
November 3rd, 2009 at 8:34 am
Kit,
I think you might have two different problems with the laptop.
This description sounds like the inverter or backlight lamp failure.
This part of the description also sounds like the inverter or backlight lamp failure.
Which one is failing? I don’t know. Most likely the inverter board. I would definitely try replacing the inverter first.
Could be bad battery.
I think you should fix the backlight problem first and if it works, move to the battery.
November 3rd, 2009 at 8:49 am
Chip,
It’s good that you were able to fix the problem without replacing parts.
I guess the inverter board had a bad contact with the backlight cable and didn’t provide enough power for the backlight lamp. Let’s see if it fails again.
November 12th, 2009 at 8:14 pm
I have an HP dv9700z with a display problem. Here are the symptoms. The display remains dark on most boot attempts, but eventually after anywhere beteen 2 and 15 reboot attempts, the screen illuminates and works properly until it is turned off (sometimes for up to 12 hrs). When it is dark there is no image. No HP startup splash screen. As far as I can see, no dim image in the beam of a flashlight (but it is hard to see with the glossy screen in this computer). The computer boots normally whether or not the display works.
An external display works properly and normally whenever it is connected by either VGA, HDMI, or SVideo connector. When connected to an external display and the internal display is not working, the display driver does not see the internal display (only the external display). When connected to an external display and the internal display is working, the driver sees both displays.
When I close the screen when the display is working, the computer goes to sleep normally, and it restarts when the lid is lifted. If the display was working prior to sleeping the computer, the display always works when the computer wakes from sleeping.
Jiggling or jostling the computer does not affect the display. If it is not working, it doesn not blink or start working when bumped…and if it is working, jiggling the computer or moving the display does not cause any changes in behavior (no lines, no blinking, no change in brightness).
I removed and reseated the connectors to the inverter, and no improvement. The computer has never had any foreign material (liquid, dirt, etc.) get into its internals.
So I am baffled. What do you think it might be? To me it sounds like it might be an inverter, except for the absence of a dim image in the dark display…but I may just not know what to be looking for..how dark can the image be?
Thanks in advance for your help…and for all the guidance you have provided me through your advice to others.
Barry
November 16th, 2009 at 12:27 pm
Dear Barry,
I have the same problem with my HP Pavilion DV9700.
It works perfectly with external monitor and LCD is always black.
Please, if you find some solution share it with me.
Regards,
KomS
November 17th, 2009 at 11:40 pm
Barry,
Most likely it’s either bad connection between the video cable and motherboard, or the video cable is bad.
The video cable is routed though the left hinge and that’s where the damage may occur.
Remove the hinge cover (as it shown in the service manual) and take a closer look at the video cable. Do you see any damage. Can you make the internal screen work if you move or touch the video cable?
Find out if moving the cable affects video on the internal screen at all.
November 17th, 2009 at 11:49 pm
KomS,
As I mentioned in the previous post, if the laptop is working fine with external monitor but internal LCD is BLACK and BLANK, check the video cable.
1. Could be bad connection. Try reconnecting it on the motherboard.
2. Could be bad video cable. Try replacing the cable.
November 18th, 2009 at 6:18 pm
Thanks for the reply, Repair Man. I have not tried to move the cable directly when the computer is on, but I have moved it indirectly. I have opened and closed the computer cover both during periods when the screen is not working and during periods when it is working. No matter how much I move the screen, it does not cause a non-working screen to work and it does not cause a working screen to stop working. Does that tell you anything? I am away from home until Friday. I will take the bezel apart then and see what happens when I move the cable directly.
I do have one new piece of information. I saw the reference to the person who recommended diagnosing inverter function using a Multi-meter with a frequency readout. If the inverter was working he got a strong, high frequency (30 – 50 kHz) reading when he held the probes in the vicinity of the inverter output. If the inverter was not working he got a weak or no reading.
I did a similar test using an oscilloscope. I found that during periods when the screen was working I got a strong (a few mV) 55kHz signal when I held the O’scope probe near the inverter output. During periods when the inverter was not working, I got not signal. So it looks like the inverter output is the issue. Doesn’t say if the problem is a bad inverter or a bad cable/connection to the inverter. But it is probably not the LCD itself (do you agree?).
What do you think of testing the input voltage to the inverter? That same person recommends testing between input pin 1 and ground. Shouldn’t that determine if the issue is the inverter or the cable?
Thanks again,
Barry
November 19th, 2009 at 8:11 am
Barry,
Try that. If there is a short inside the cable, you should see changes on the laptop screen when you move the cable.
Are you talking about this guide? I tried that (even purchased a new Fluke multimeter
) but it didn’t work for me. By the way, I love my multimeter. 
I think the inverter board works properly only when it’s loaded by the backligth lamp. Yes, if the backlight lamp is working fine you can get high frequency readings. But what if the backlight is bad? I think in this case you will not get those high frequency readings even if the inverter is good, because it’s not loaded. I could be wrong though.
… or the inverter board is not getting any power from the motherboard and there is no light because of that….
I think you can safely test voltage on the input. Yes, it’s pin 1 and ground. I did that. You should get something like 10-20VDC.
I’ve been fixing laptop for 5 years and here’s what I found. The best way to find out if you have issues with inverter or backlight lamp is testing the laptop with another known good inverter or backlight. Check it out: http://www.laptoprepair101.com/laptop/2009/05/04/how-test-lcd-screen-inverter-in-laptop/
Could be the motherboard failure. Maybe one of the components is failing. This component fails most of the time, but if it starts, it works properly until the laptop is turned off. That’s my guess.
November 23rd, 2009 at 3:55 pm
Hi Repairman. An update. I tried the cable wiggling test with the bezel removed. No effect on the display.
I tested the input voltage to the inverter and it was 15 volts DC whether the display was working or not.
The “guide” link you noted in your last response is the test I did to test the inverter output..but I used an oscilloscope instead of a multimeter. The test gave me consistent results…a stable 55 kHz output when the display was working, and no output when the display was not working.
It really looked like it is the inverter. But since then I have replaced the inverter (twice) and there was no change in the symptoms…the display works sometimes and not at other times. Maybe your hypothesis about the LCD having to “load” the inverter is correct?
You speculate that the problem might be a motherboard failure. What part might it be, considering that it always works on an external display..and it always sends the proper 15 VDC signal to the inverter?
Finally, I really don’t want to buy a backlight to do that inverter test. It know that I will wind up breaking the light and producing a hazardous mess from the mercury inside. Considering that I have tested 3 inverters and the symptoms don’t change, I have to believe that the problem is elsewhere…and probably the LCD itself. I won’t invest another $300 or so into this computer for a new 17″ display. So for now I will thank you for your suggestions, and continue to limp along with the computer as it is.
Thanks,
Barry
November 26th, 2009 at 2:04 pm
Barry,
It’s very unlikely that all inverters are bad. Most likely there is a problem with the backlight lamp.
I don’t think that your problem is related to the motherboard failure because the LCD screen works intermittently. I would test the laptop with another backlight lamp first.
Check out LCD screens on eBay. Some brand new LCD screens are very inexpensive. You can find a new one for about $100.
November 27th, 2009 at 11:50 am
Ok Everything ok with the removal of the lcd inverter,
but please cannot find this lcd inverter:
PWB-IVC12138T/B1-E-LF
any help please where to find it (I have google it)?
November 27th, 2009 at 12:28 pm
I came to the same conclusion that you did and decided to buy a backlight for testing. As soon as I did that, it seems like the display has healed itself (so far about 6 successful reboots in a row). Once it starts acting up again, I will get a backlight and test it. If the screen’s backlight is bad, I will try and replace it…and if I screw up the screen, I will buy a new screen thru eBay. If the test backlight works consistently, then I will probably do what you suggest and replace the screen with one thru eBay.
Thanks for all of your help and guidance.
Barry
November 28th, 2009 at 12:11 pm
Costas,
Try searching on eBay using the laptop model number and part name. For example, if you have a Acer Aspire 5100, search for “Aspire 5100 inverter”.
December 2nd, 2009 at 4:58 am
Blank screen when I turn on the laptop. DV9000 w/Vista.
Screen is lit. I can change the contrast Lighter or Darker. Laptop works with external monitor, but I cannot get it into safe mode.
Would it most likely be the inverter or the screen? There are images.
Any suggestions…
December 16th, 2009 at 1:18 am
Hello , i have a question about the inverter failure , but i think it’s not a lamp or inverter , but the motherboard failure, so it’s my “white hair” problem…
the backlight fail in random situations , so, can’t be the lamp becouse it works for hours and inverter too…
sometimes the backlight comes to blink a lot and comes off , i test all cables , connectors , all “mechanical” parts, all ok, now after read this experiences i try to check the pin1 and get 20v , pin2 and 20v , pin3-2v , pin4-0v , pin 4 and 5 is ground, i check possible bad resistors, caps, solders, and seems to be ok , to solve this , i need help to understand a little deep how this inverter works to find a way to get my backlight ok again
i think this voltages are wrong , the motherboard is possible sending a impossible value to inverter bright adjust on pin 2-3 and the inverter goes off, the model of inverter is VA250E – G75-0.3 on white label and LM10W ver 0.3 silked on inverter.
i want to know if i can change the source of pin1 to get a stable 15v and don’t connect pin 2-3 i can get the backlight on again with this inverter, thank’s!! sorry for my very bad english.
December 22nd, 2009 at 12:46 pm
alright i just replaced the lcd screen on my laptop which is a dell inspiron 4150 the light shows up and you can see the backlight working but there is no picture a blank screen
December 22nd, 2009 at 12:52 pm
alright i just replaced the lcd screen on my laptop which is a dell inspiron 4150 the inverter is working but there is no pictureand a blank screen but there is glow in the back
January 1st, 2010 at 3:32 am
Hi-I have a HP DV6000. The screen has a pink/red tint from the moment I turn it on, even before Windows loads. Do you think the backlight or the inverter or LCD screen is causing this problem? I reseated the display connector on the motherboard but that didnt fix the problem. Thxs. (BTW, the image is clear not fuzzy).
January 4th, 2010 at 11:27 am
Thanks for all of the images and instructions. From the looks of it, my HP Pavilion dv6565 has a bad inverter. Where would you recommend purchasing a replacement part?
January 9th, 2010 at 11:05 pm
Hello!my acer aspire 4715z laptop shows blank screen after power on..everything is fine except the blank display..however,there are still back lights that light up in the monitor..what this could be the problem?thanks for the help..
January 18th, 2010 at 1:56 am
Hello there.
thank you for a very informative site.
i dropped my laptop a few weeks back and I’ve had the dark screen problem ever since.
I’ve tried reconnecting the cables for the FL inverter but I don’t have good results. Display is fine on an external monitor.
I just want to know if it is possible to pinpoint the broken hardware (inverter or lamp) by the way it messed up i.e me dropping it.
I would also like to know how compatible inverters are. The one i’ve got is j9084 1.00
Toshiba satellite.
Thank you again mate.
Sam.
January 19th, 2010 at 10:16 am
Hey guys,
Can someone help me with my laptop problem? I’m wondering if this is a graphics card problem or a screen inverter board problem.
On the side left of my laptop screen and sometimes on the left half of the bottom screen, there’s a pink glow/splash/tint. It’s gotten longer over the past week.
January 19th, 2010 at 11:15 am
Hi! I have a Toshiba A135 S2266 laptop. The powers light on the computer itself comes on and the fan starts up just fine but the screen stay blank both internally and externally and the light on the cd drives is amber instead of green. The cd drive will not open when the eject button is pressed, it only open when i put a pin in the little hole on the side. Could this be a problem with the motherboard, memory or inverter. I have opened it and double check all the wires and the MB, they look fine and have no burnt scent. Please help me, i’m in dire need.
January 19th, 2010 at 11:01 pm
JahJah,
First of all, I would check laptop memory (RAM). Most likely you have two memory modules installed and it’s possible that one of the modules failed.
Try removing memory modules one by one and test the laptop with each RAM module separately in each slot.
I believe when the drive is working the light is always amber, it never turns green. Isn’t it?
Remove the DVD drive and turn on the laptop. Maybe the DVD drive is bad and shorting the whole system somehow. Just a guess.
January 19th, 2010 at 11:06 pm
C,
Most likely this is not related to the graphics card failure. A failed video card would affect image on the entire screen, not just a part of the screen.
Just in case test your laptop with video on the external monitor. If the external video works perfectly and there is no pink glow/splash/tint, the problem is not related to the graphics card.
I think it’s either failing backlight lamp inside the LCD screen (more likely) or failing inverter board (less likely).
From my experience, when the inverter board fails, the backlight lamp stops working completely. In your case only one part of the screen is affected, so I assume this is the backlight lamp failure.
January 19th, 2010 at 11:21 pm
Sam,
You said the screen is dark, but the image is still there, correct?
Most likely you damaged the backlight lamp.
January 19th, 2010 at 11:39 pm
vinz,
Did you test the laptop with an external monitor? Can you see the external video?
January 19th, 2010 at 11:59 pm
Michele,
Find the inverter part number and google it or search on eBay. Buy from a reputable place.
The part number will help you a lot.
You can find the part number in the maintenance and service guide (can be downloaded from HP website).
January 20th, 2010 at 12:03 am
bill,
You’ll have to test your laptop with an external monitor. If the same problem appear on both internal and external screen, your problem is related to the video card failure.
If red tint appears only on the laptop screen and external video works perfectly, most likely this is the backlight lamp failure. The lamp is mounted inside the LCD screen and very hard to replace. It means you’ll have to replace the entire LCD screen.
January 20th, 2010 at 8:53 am
Hi Repairman, today I had removed the RAM but the problem wasn’t rectified, so I took out the Inverter and replace it with another one from a different model Toshiba laptop and the screen lights up just perfect but I didn’t leave it hooked up long enough to observe the cd drive cause of the fear of ruining that one. I also did the procedure vice versa and it was indeed a bad inverter cause the known good laptop screen stayed blank. my inverter has 7 pins and the other one has 6 hence the reason that I had removed it quickly.
January 22nd, 2010 at 5:53 pm
when i start my toshiba satelite a135 nothing is lightin up but i see picture in the back , bought it a new inverter still nothing picture still in the backgroung… any sugestins.. thnx
January 27th, 2010 at 3:11 pm
robija,
It’s possible that you have a faulty backlight lamp inside the LCD screen.
You can test it with a known good backlight lamp: http://www.laptoprepair101.com/laptop/2009/05/04/how-test-lcd-screen-inverter-in-laptop/
February 6th, 2010 at 1:31 am
I have an acer 5610 about one fifth of the lcd on the right is black but on an external monitor it shows it all what could be wrong?
February 10th, 2010 at 11:01 pm
Jorge,
Can you see the entire desktop image on the working part of the screen and it looks kinda compressed, or the black stripe on the right side covers part of the desktop image and makes is unusable?
February 11th, 2010 at 7:33 am
Hi, i have lenovo y410, the problem is with the lcd display, after it on then the dispaly start to vibrate vertically. Sometimes, the image which should at the top but it can be view at bottom of lcd display.
I’m not sure the lcd or inverter failure… Anyway how to test the inverter?
Thanks bro
February 11th, 2010 at 7:42 am
Hi, (continue) in my case with my lenovo Y410. I already tested to hooked it up to an external LCD and the screen on the external monitor is just fine. Just for your info. Any help is appreciated.
Thanks
February 12th, 2010 at 1:44 pm
senaville,
Nope, it’s not related to the inverter board, that’s for sure.
That means the video card is working properly.
I think it’s either failing LCD screen (more likely) or problem with the video cable (less likely).
I would try replacing the LCD screen first.
February 18th, 2010 at 7:18 am
Tq on your advise…
February 19th, 2010 at 8:38 pm
Hi,
I spilled water on my laptop hp compaq nx7400. Now when i try to turn my laptop on it starts normally and then screen goes blue.
Please help me. After I spilled water I dryed it with blow drier.
I don’t know much about laptops.
February 20th, 2010 at 2:40 pm
Ivana,
It’s necessary to disassemble the laptop and take a closer look at the internal parts. I guess you’ll have to take your laptop to professionals.
February 22nd, 2010 at 10:42 pm
You are an absolute champion, This had been driving me crazy since i had my brand new laptop 3 months…. i put up with it for 2 years.
Then finally it stopped backlighting at all like you said.
I was about to remove the screen completely to use it as a 65w server, and just terminal in… lmao.
Russ.
February 23rd, 2010 at 4:08 am
I got a odd problem, got a dell vostro 1710 and the screen got sat on. Got the replacement screen and had issues with the frame so had to swap with old frame to get holes to line up. now when it boots I do not see the bios screen but the black screen lights up some. but when I get in windows and see my desktop 50% of the time I see it OK, I do have it hooked to an external monitor so I know the computer is AOK. do you think my inverter is bad or the new screen? Have you had to replace the frame of a lcd, maybe I got something messed up there? any help would be great.
February 23rd, 2010 at 2:13 pm
Jman,
Can you see the BIOS screen on the external monitor.
What do you see on the desktop the other 50%?
Can you see a very faint image or it’s completely blank?
Have you checked connections between the video cable and LCD screen/inverter board.
February 24th, 2010 at 4:24 am
I have an Acer Aspire 5610Z Laptop which has been damaged by lightning. Up to now I have not been able to find someone who can definitely say what is damaged. When the lightning struck there was a flash from where the adapter connects to the laptop and the machine went off only to immediatly power on again, it then continued working fine for a while. When I returned to the laptop later it had switched off and would not restart. I have tried various recommendations, for instance remove the battery for 30 sec., connect to an external monitor and lastly to replace the Inverter. None of these efforts produced positive results. There is no sound or anything remotely visible on my laptop now.
Could or would you be able to give me some idea as to what may have been damaged and if it would be worth repairing.
Thank you for your advice.
February 24th, 2010 at 10:51 am
Elizabeth Barnard,
Was the AC adapter plugged when the lightning struck?
Maybe the lightning damaged the AC adapter. After that the laptop worked until the battery got discharged. Now you cannot turn it on because the battery has no charge and AC adapter is dead. I would test the AC adapter first.
If the lightning struck when the AC adapter was unplugged and now the laptop is dead, probably it damaged the motherboard.
Can you start the laptop just from AC adapter when the battery is removed? Can you see any LED lights on the front when AC adapter is plugged in?
February 24th, 2010 at 1:18 pm
Yes the Adapter was plugged in – I was using the laptop, and yes my husband checked the adapter. I cannot start the machine at all; with or without the battery removed and just the adapter. When I removed the battery the first time it powered up and the screen showed briefly, but then it went dead again. I did see the power and battery lights come on once or twice but now these also don’t light up any more. The person who changed the Inverter for me experienced the same thing at the time that I was. Unfortunately he is unexperienced and perhaps did nor insert the converter correctly.
February 24th, 2010 at 1:45 pm
Elizabeth Barnard,
This is not inverter related problem. You still should be able to start the laptop when inverter fails but the image on the screen will be very dark.
In your case the laptop will not turn on at all and there are no LED lights. Assuming that your AC adapter is good, I’m almost positive you have bad motherboard.
February 25th, 2010 at 12:06 am
If this is the case is it worth it to repair my laptop?
February 25th, 2010 at 9:29 am
Elizabeth Barnard,
It depends.
If you can find inexpensive replacement motherboard and replace it yourself, probably yes.
If you decide to take this laptop to the repair shop, it will be expensive. Probably it’s better to save money for a new laptop.
February 26th, 2010 at 1:52 am
Thank you very much for your kind assistance; it is much appreciated. I will have to look at all the angles.
Good Luck with your work.
February 26th, 2010 at 9:19 am
I have a Dell Inspiron 1545. The screen cracked so I replaced it. The new screen was very dim. I tried the old screen again and it was also dim. It works fine on an external monitor.
I went to a computer repair place, told them I thought it was the inverter, and they took it in for a free diagnostic. They tested my parts on another machine and tried using parts that worked in other machines on my machine (screen, inverter, cables). That didn’t work so now they say they think it is the motherboard and I am supposed to call them for a price quote on that.
If everything works fine through an external monitor should I still replace the motherboard or are they simply missing something? What else could it possibly be?
February 26th, 2010 at 10:02 am
Brad,
If your parts worked on another laptop and parts from another working laptop didn’t work in your machine, most likely there is a problem with the motherboard.
By the way, check the lid close switch. I don’t know off the top of my head if the lid close switch in your laptop is magnetic or regular button, but that could be the problem. It’s possible that the lid close switch got stuck in the “closed” position and the laptop “thinks” that the display is closed even when it’s open.
If the lid close switch is a regular button, try tapping on the switch, hopefully it will work.
Did you purchase a compatible replacement screen? Maybe the screen wasn’t compatible and you fried the motherboard when installed it into the laptop.
Just in case. I’m not sure if it’s going to help but try it anyway.
Boot your laptop with an external monitor. Go to the device manager and delete (uninstall) the display adapters and monitors. Restart the laptop and test again.
February 26th, 2010 at 10:11 am
I actually mentioned the possibility of that button/sensor being stuck and the guy just said “I’m sure the technician checked it.”
I ordered the wrong screen at first but didn’t try to install it since I could tell they weren’t compatible but now I’m sure I have the right one. I’d try the display adapter uninstall but the repair place still has my laptop. I’ll suggest that they try that though.
I hope that replacing the motherboard works. If not I’m out quite a few bucks and still left with a mystery machine.
Thanks RM
February 27th, 2010 at 11:54 am
Hi,
I am using the HP Pavillion dv2842se laptop from past 2 years. I never face any problem till now.
Two days back I shutdown the laptop normally after my work. After 2 hours I tried to start the laptop but the power button and HP quickplay buttons are not working. So I tried to start the laptop with HP quick play remote. From remote it is starting but my screen is black. I noticed that if I look at my screen from an angle with an external light, I can see the icons and everything. What may be the problem.
Thanks,
Kiran
February 27th, 2010 at 12:02 pm
Brad,
Hopefully they did.
February 27th, 2010 at 12:03 pm
KiranKumar,
What happens when you press on the power button? Can you hear any noise coming from the laptop?
Also, when the AC adapter is plugged. Can you see any LED lights on the laptop indicating that the laptop is getting power?
The faint image on the laptop screen could be related to the inverter/backlight lamp failure but I don’t think this is the only problem with the laptop. You said the power button stopped working and it’s not related to the inverter/backlight failure.
If both the power button and screen backlight failed at the same time, there could be a problem with the motherboard.
February 27th, 2010 at 9:14 pm
Hi Repair Man,
Repair Man: What happens when you press on the power button? Can you hear any noise coming from the laptop?
Also, when the AC adapter is plugged. Can you see any LED lights on the laptop indicating that the laptop is getting power?
KiranKumar: When I press power button no noise and nothing is happing. And AC Adapter plugged I see the power charging LED lights on laptop.
Repair Man: If both the power button and screen backlight failed at the same time, there could be a problem with the motherboard.
KiranKumar: If problem with the mother board, is possible to start laptop. Because, when I use the quickplay remote to start laptop, it is starting and all the LED lights are glowing(Power and quickplay) and problem is screen backlight.
Thanks,
KiranKumar
February 27th, 2010 at 10:20 pm
KiranKumar,
The backlight problem could be related to the inverter board failure. You can try replacing the inverter.
But I don’t know why your laptop not starting when you press on the power button. Could be bad power button board, bad cable, bad connection, etc… I cannot tell without looking inside the laptop.
February 28th, 2010 at 4:35 am
Hi Repair Man, Thanks for the reply.
I will try to replace the inverter board. But how much it costs?
Model is HP Pavillion dv2842se.
Thanks.
KiranKumar
February 28th, 2010 at 11:15 am
KiranKumar,
I don’t know. You’ll have to search for a new inverter. The best way to find the right part is searching by the HP part number. The part number should be somewhere on the inverter board and it looks like XXXXXX-001 (where XXXXXX is a string of numbers).
Find the inverter part number and google it.
This guide explains how to disassemble an HP Pavilion dv2000 series notebook and access the inverter board:
http://www.insidemylaptop.com/replaced-damaged-lcd-screen-in-hp-pavilion-dv2000-notebook/
Again, it’s possible you have more than one problem in the laptop and replacing the inverter board will not help to fix issue with the power button.
March 2nd, 2010 at 8:22 pm
Repair Man,
I got my laptop back from the shop and did the last ditch thing you said below before I sent it off to Dell.
You said to “Just in case. I’m not sure if it’s going to help but try it anyway. Boot your laptop with an external monitor. Go to the device manager and delete (uninstall) the display adapters and monitors. Restart the laptop and test again.”
And now it doesn’t display anywhere, not dimly on the screen nor on an external monitor. Is there anyway to “undo” that uninstall without access to a screen?
March 2nd, 2010 at 9:44 pm
Brad,
This is not normal.
If all hardware operates properly, uninstalling the display adapter and monitors will not do any damage. I’ve done it many times myself on many different laptops. The laptop should start properly, detect all missing (uninstalled) hardware and reinstall drivers automatically. Apparently, hardware in your laptop do not operate properly.
Here’s what you can try. Turn off the laptop, unplug the AC adapter and disconnect the battery. Wait for a few minutes, connect the adapter and try turning it on again.