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”
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Pages: « 18 … 11 10 9 8 7 6 [5] 4 3 2 1 » Show All
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 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 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
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.
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 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 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 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 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 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 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 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 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 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 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 5th, 2009 at 1:05 pm
Well the new display inverter fixed it all,works fine all the way!
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 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 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 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 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.
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.
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 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 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!