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.
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August 13th, 2007 at 10:14 pm
R.KUMAR,
My first guess would be the inverter board. Inverters fail more often than backlight lamps.
Unfortunately, I cannot guide you through the disassembly process because I’ve never worked with Fujutsu laptops.
Take a look at disassembly guides for Toshiba laptops, they could be similar.
August 12th, 2007 at 12:03 am
I have a Fujitsu Siemens AMILO pro v2030 laptop ,Now recently one day screen became very very dim (not visible in darkness).Please suggest problem may be with backlight/inverter?And how to open screen.We have no technical person in nearby region who can handle this problem.
August 6th, 2007 at 3:30 pm
My IBM T42 (14.1″) has following display problem: when starting Windows or getting back from sleep/suspend (turn the LCD on), the color in the both sides of the LCD are pink/hue tone while the color in the center of the LCD is normal. Then it brighter to normal after a few seconds (say 30 sec). The same thing happen when I lower the LCD brightness (lower than 4/8). It is working fine with external LCD monitor. Is this an inverter issue? Or the back-light problem?
Thank you,
Ken
July 26th, 2007 at 5:38 am
I have a gently used older laptop (Compaq Presario 1277) which had been working fine and the screen went suddenly black. If I hook the computer to an external monitor, it works fine. Is it worth
repairing since the computer is >7 years old and not nearly as powerful as a newer one? If it’s just the inverter, can I replace it myself?
July 25th, 2007 at 9:53 am
re: compaq v2000 no image whatsoever – comments 112/113
your suggestions in comment 114 have proven to be right on. i was lucky to get my hands on a hp dv1000 screen. i put the dv1000 screen in the compaq v2000 and a nice clear image came up!
i took both screens apart and swapped the video cable (even though they don’t quite the same and the cable routing is not the same) and the dv1000 cable worked with the v2000 screen and v2000 inverter. the dv1000 screen stopped working with the v2000 cable. –> need new working v2000 lcd cable.
thx for your suggestions! they/you were very helpful! keep up the great work!
July 25th, 2007 at 9:17 am
I need screen inverter for my laptop part # is P/N:412802800001
Please help me
July 22nd, 2007 at 1:39 am
My notebook screen flashes when I first turn it on, but then goes black. I do see that there are images on the screen, and have deduced to either the lamp or the inverter needs replacing. Also when turning off, it flashes again, but only for a second. How would you be able to tell if its the INVERTER, or the CCFL?
Poor college student so as much research is being taken, haha! Either try a $8 CCFL, or go for the $60 inverter! I’m sure you understand! Advice would be very well appreciated!
July 22nd, 2007 at 1:33 am
oops, forgot the link…
http://www.hk3d.com/temp/InverterReplacement.pdf
July 22nd, 2007 at 1:33 am
I made a walkthru on replacing inverter on a Dell Inspiron 8600 while i was doing it. hope it helps people.
:kk
July 21st, 2007 at 2:12 pm
Lee Johnson,
If a known good inverter doesn’t fix the problem then probably you have a faulty backlight lamp. Unfortunately the only way to find out is testing the laptop with a good backlight lamp.
Make sure the video cable is seated properly on both ends and makes a good contact with the motherboard/video card and the LCD screen. If this model has a discrete video card, make sure the video card itself is making a good contact with the motherboard.