Do you have a problem with the backlight on your laptop? If yes, you are not alone, that’s one of the most common laptop problems. In most cases the screen inverter is the culprit. Here are some LCD screen backlight failure symptoms that could be related to a bad inverter board:
- Laptop boots as usual but after some time the screen blacks out. You still can see an image on the screen but it’s very dim. You might even use a flashlight to see it better. Sometimes the backlight comes back for a while but then goes off again. In some cases you can turn the backlight on if you tap rapidly on the lid close switch.
- The screen always stay black and the backlight never comes on but you still can make out an image on the LCD. It’s dark, but the image is still there.
-In some cases you might hear a buzzing noise coming from the area where the inverter board is located, it’s on the bottom part of the display assembly.
NOTE: if you cannot see an image on the screen, most likely you have a different problem and there is nothing wrong with the screen inverter.
Other related articles:
Laptop has bad video on the LCD screen. What is wrong?
Notebook display assembly diagram. How image appears on the screen.
How to troubleshoot and fix laptop video problems
How to replace laptop backlight lamp (CCFL)
Here’s an example of replacing the FL inverter board on an IBM ThinkPad T41 notebook. This guide will work fine for any other IBM notebook. Replacing screen inverter on other notebooks like Dell, HP, Toshiba, etc… will not be much different.
First of all, unplug the AC adapter and remove the battery.
In order to access the inverter board you’ll have to remove the LCD screen bezel. On most laptops screws are hidden behind screw seals. In this case we have 5 screw seals on the front. Carefully remove the seals with a sharp object and glue them on the LCD bezel, in this case you will not lose them. Remove all screws and mark them somehow so you are not confused when you assemble the notebook back.
Some laptops also have screws on the side of the display. This notebook has 3 screws on each side. Remove screws seals and then remove screws.
Start removing the LCD bezel with all fingers. Carefully wiggle the bezel to release plastic latches. Never use any sharp object during disassemble because you can accidentally damage the screen.
If latches are very tight you can use a guitar pick to unlock them. Insert the guitar pick between the LCD bezel and cover and carefully move it alone the side.
This notebook allows you to replace the inverter board without removing the LCD bezel completely. Lift up the bottom part of the bezel and remove one screw securing the inverter board to the LCD cover. This location is very common for the screen inverter. On most laptops you’ll find it under the display bezel below the screen.
Carefully lift up the FL inverter and rotate it a little bit. Unplug cables on both sides. The left side of the inverter board connects to the video cable, the right side to the backlight bulb (CCFL tube) inside the LCD screen. Remove the inverter and replace it with a new one.
To find a new inverter board (and any other spare part too) for any IBM notebook you should use the FRU number from the part.
If you find this article useful, please consider making a donation to the author. Thank you!
February 19th, 2010 at 10:43 am
do not replace inverter repair it
inverters are not hard to repair,
example most burnt inverter are repaired by changing a
link which is like a fuse. it is a small black square by the plug of the inverter markd by T or 0,00, or 000 which means it is a fuse resister replace it. in some case if it has capacitors then a cap replacement would do it.if any problem send me a picture of your inverter and i will place a repair tecknick for it.any electronic,refrigiration or computer probem i would be glad to help
February 16th, 2010 at 12:46 am
Hi, thanks for the helpful article. My Dell Inspiron 6000 started experiencing these same issues about 2 years ago. During startup, I see the Dell splash and Windows screen briefly, accompanied by a red tint and strange buzzing noise. The screen then immediately turns black. From what I’ve read online, it seems like I have a problem with the inverter or backlight? I have been hooking this broken laptop to an external monitor for nearly 2 years now in order to continue using it. The laptop works fine on this external monitor. Since I have another laptop to use, I have been putting off getting this problem fixed. I’m just wondering — is it okay to keep using this laptop with a broken inverter/backlight while hooked to an external monitor? Would this cause more damage in the long run? I want to avoid spending extra money to fix a laptop that I only use at home now and just want to make sure this won’t create further damage. Thanks!
February 15th, 2010 at 12:38 pm
Hi there, I have a Toshiba Equium p200 series laptop where the laptop screen is very dim on startup and then goes black. I shone a bright light on the screen and the log on screen is visable. I connected to a external monitor just to confirm.
I replaced the Invertor – Still problem exists.
I replaced the LCD screen – still problem exists.
I assume as the image is displayed properly there is nothing wrong with graphic card or motherboard…. its driving me nuts…. please help!?
February 14th, 2010 at 2:35 pm
as i open the laptop screen past 45 degrees the screengoes blank.
below that degree of opening the screen is perfect, no problems.ing this
Why am I getting this problem? Is the video cable that connects
the screen tom the motherboard, being stressed beyond the angle of opening?
February 12th, 2010 at 12:45 pm
Al Bee,
Sounds like a problem with the backlight lamp. I assume that your new inverter was good.
The pinkish hue is one of the symptoms of failing backlight lamp.
It’s not easy to replace the backlight lamp. I would suggest replacing the entire LCD screen.
February 12th, 2010 at 12:34 pm
I have a Toshiba M105-s3041 (14.1 screen) laptop that has LCD Problems. A month ago the screen started flickering and eventually went out later that day. You can see the faint image on the black LCD of the laptop.
I replaced the inverter board myself and had these results. LCD screen came on but flickered (like a phloresent bulb warming up). After 10 minutes, the LCD came up to full brightness. But then started flickering again, got the pinkish hue (hue comes in and out), and LCD went black 30 minutes later.
I have the laptop hooked up to an external monitor and that image is fine. If I toggle through to the multi-monitor mode (Fn+F5) the laptop LCD will come back on again, but still with flickering, pinkish hue (in and out), and eventually goes black. The external monitor is fine, and you can still see the faint image on the black LCD of the laptop.
There is not an external shut off button for the laptop lcd screen on this model. Pressing anywhere, flexing, or flipping the bezel OR the laptop base shows no effect on the laptop LCD.
Is there anything else I can check on the LCD that could be causing the flickering?
I looked at your great backlight lamp replacement guide. I have some light experience with electronic repair, but lamp replacement may be a touchy repair. I can replace to a new LCD screen for under a hundred.
Your thoughts?
Many thanks for all your help!
January 19th, 2010 at 6:13 pm
T42 IBM – the same problem. I was so happy to find your article thinking to myself – bingo! Ordered inverter board, installed……same problem
If I connect my laptop to external monitor – it works just fine (does that mean that mother board is OK? should I replace the lamp?
January 14th, 2010 at 1:54 pm
Great article – thanks.
Have an HP Pavilion DV6000. Initially showed the classic failed inverter symptoms. Replaced the inverter and the backlight worked, but there was a noticeable flicker. Tried checking for driver settings etc. but there did not appear to be any issues. After approximately one hour the backlight went out. Contacted the inverter supplier and, after verifying that they had provided the correct one, they sent out another inverter. Hooked up the new inverter and same result – backlight works but has a noticeable flicker. Contacted the supplier for suggestions on troubleshooting but their only solution was to return the inverters for a refund.
Any suggestions besides looking for a new supplier?
Thanks!!
January 12th, 2010 at 12:02 am
Hello,
My Toshiba shows a black screen, though I can see what the laptop shows when a lamp is in front of the screen.
I’ve changed the inverter, according to your suggestions, but no luck.
Is there a problem with the inverter, it has a light on it that turns on, it goes stronger as I upgrade the brightness of the lcd screen or dimmer vice versa.
If I have the inverter out of the laptop, it still works the same way.
Bad inverter or different model of inverter of my laptop;
What do you think?
December 28th, 2009 at 9:26 pm
I have the same problem as “Dave” on a Dell Inspiron 8600. The screen is still usable, very much so, but the highest brightness setting is no longer very bright. I’ve no interest in changing the lamp, inverter maybe.