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.
Laptop parts | Repair Man | 
December 26, 2008 3:14 pm
440 Responses to “Screen inverter board”
Pages: « 18 … 11 10 9 8 7 [6] 5 4 3 2 1 » Show All
Pages: « 18 … 11 10 9 8 7 [6] 5 4 3 2 1 » Show All
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 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 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 10:14 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 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 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 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 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 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 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 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 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 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?
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.
August 28th, 2009 at 4:53 am
hi how do i remove the back light on prsario c500
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 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 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 11th, 2009 at 7:54 pm
Thanks, very good information.
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???
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?
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 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 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 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.