Screen inverter replacement. Fixing laptop backlight problem.
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.
Entry Filed under: Replacing Screen Inverter
311 Responses to “Screen inverter replacement. Fixing laptop backlight problem.”
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Pages: « 32 … 11 10 9 8 7 6 5 4 3 2 [1] Show All
February 11th, 2007 at 9:15 am
Jason Denniston,
The best way to test the inverter board would be replacing it with a known good one.
I usually hook up a test backlight bulb first (I remove them from cracked screens) and if it will not light up I install my test inverter and test it again.
I’ve been searching for the instructions on how to test the screen inverter with a voltmeter, but haven’t found it yet.
February 10th, 2007 at 6:26 am
I have a problem with my thinkpad r32 everytime i boot it it says
ERROR
Resource conflict - Allocation error static node # 02
ERROR
Resource conflict - Allocation error static node # 07
PLZ HELP
February 9th, 2007 at 1:49 pm
I have an IBM T40 and it boots up fine and will work for ten minutes or so… then the screen will freeze/flicker or turn black, especially if I try to move it. It wont work again right away but if I leave it for a few hours I get another 20 minutes of work done on it.. I did all the virus scans etc… but now im a bit lost. Any ideas?
sincerely,
poor college student trying to save a 5 years old laptop
February 7th, 2007 at 11:25 pm
my ibm laptop power s working but screen not working i don’t know what happend
February 7th, 2007 at 12:08 pm
Is there a way to test the inverter board to determine it’s actually the inverter board and not the bulbs?
February 6th, 2007 at 10:46 pm
Very timely - the inverter in my T22 died yesterday. I had trouble getting details on the inverter at the IBM/Lenovo site - the FRU number of 10L1402 didn’t seem to exist. On the phone to them today, they told me that the part has been replaced with a new FRU of 91P7739, which explains why I couldn’t find it.
Thanks for the very useful article. I hope to have mine fixed in just a couple of days once the new inverter arrives.
February 6th, 2007 at 9:42 am
Carmen,
Maybe the inverter board is located on the side from the LCD screen? I just opened up a Dell Latitude CSx display to check the inverter board location and found it on the right side from the screen.
February 5th, 2007 at 9:59 pm
[…] Replacing LCD screen inverter […]
February 3rd, 2007 at 9:56 pm
How about if I tell I can’t find the Fl Inverter in my Dell latitude Cpx when I open it? Could you tell me where it should be at them? It’s not where it say here on this page. Thank you.
January 31st, 2007 at 2:16 am
Hey its great to see a new post here. I subscribed to the feeds months ago and I totally forgot about the site until I read this post. Nice write up! I have always enjoyed reading this site. I guess posts come when repair jobs come… huh?
Well, I guess everyone should pool together and break their laptops and mail em’ in… I am looking forward to reading more articles written by you in the future.
Best Regards,
Garry Conn