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 (not even very dim image), 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.
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February 4th, 2013 at 4:52 am
@ Charlotte,
The backlight lamp installed inside the screen. When you buy a new screen it always come with a backlight lamp inside.
Normally, you don’t get a new inverter with a new screen. You have to purchase it separately. NOTE: some Dell screens come with the inverter board attached.
January 22nd, 2013 at 4:20 pm
does the backlight and inverter come with a new screen
May 11th, 2012 at 8:04 am
im trying to replace the inverter for my packard bell easynote TJ74, but they dont seem to exist !! anywhere
so my question is, is it ok to use an inverter for another type of easynote ……e.g. TJ75 or TJ73, without any problems, or do i have to strictly stick to my model ??
thank you
April 10th, 2012 at 5:28 pm
Absolutely. Monitors connect to the motherboard via VGA cable, and the video card it connects to talks to its controller built into the motherboard. As long as these things are working appropriately, there should be no problem.
April 10th, 2012 at 5:26 pm
Absolutely. Monitors connect to the motherboard via VGA cable, and the video card it connects to talks to its controller built into the motherboard. As long as these things are working appropriately, there should be no problem.
April 10th, 2012 at 2:03 am
Hello, can a LCD of the same size, Res, and back light config. Be exchanged if they are made by different manufactures? Would the inverter and screens of each be sending and receiving the same electronic information? A Samsung panel and a Philips panel both wxga, 15.4”, both single lamps. Can you assume that both would work in place of the other?
April 9th, 2012 at 5:31 pm
My desktop screen will flash on for a split second when the computer boots, then it goes off. If I turn it off and then back on, I see it again for a flash of a second. What I’ve been doing so far is unplugging the power cable for ten minutes and then rebooting. It’s working for now. I’ve been told it’s definitely the backlight. If so, how do I replace the backlight bulb, and how much will this cost me?
March 25th, 2012 at 2:09 am
i am having the same problem as there is no backlight, even i am able to see a very faint display. the laptop m using is ibmt23.
now my question is that, whenever I tap my lcd , backlight comes and it remains until he computer is turned off. there is also a display cable.. whenever i tap that cable lcd works fine.. so is the problem with my lcd cable or my inverter board??
February 2nd, 2012 at 8:18 am
@ s44xD,
Did you buy a used inverter or new one? It’s possible your new inverter is defective.
Did you notice any change after replacing the inverter? Maybe the screen stays on for longer time?
In short, here’s what could be wrong with your laptop:
1. Your new inverter is defective.
2. The backlight lamp is failing.
I would try replacing the inverter board again.
January 25th, 2012 at 5:19 am
Hi there! I just replaced my backlight inverter after it and now the display works again…. works for only up to 5 minutes from booting the system. does it mean i replaced my old inverter with just another broken one?
I am at a total loss. what to do now?