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.
If you find this article useful, please consider making a donation to the author. Thank you!
September 2nd, 2007 at 1:06 pm
It sounds like I have a similar issue to Bobby. I have an hp dv1207. My screen went dim about a week ago. I read up online and all symptoms pointed to an inverter problem – so I replaced the inverter.
Now, strangely, my screen comes up bright when my computer is first booted (this didn’t happen before). After about 5 seconds, the screen goes dim again. When I switch to an external monitor, my screen will flash up for a few seconds, then dim. The external monitor displays without a problem, so I know the computer is working.
Could my new inverter possibly be defective??? It obviously did something to help (I’m assuming since the screen will light up now, even if only for a second) but doesn’t seem to have fixed the entire issue.
Any advice you can offer is GREATLY appreciated.
Bobby – if you find anything out about your issue, do you mind e-mailing me at joshheidler@hotmail.com?
Thanks!
September 1st, 2007 at 9:17 am
I have an HP Pavilion dv1000. I have a backlight problem like no other. I replaced the inverter… no dice, I replaced the entire screen/lamp…. nuthin. I even replaced the mother board. Still… all that happens is that when I power on the light comes on for a sec then goes black. It does the same when I switch to the external monitor (which I am using right now). I am now at a loss. Help me Obi Wan.
August 29th, 2007 at 7:02 pm
I have a 4150 Dell Inspiron with a bad inverter, part # IV11153T/ I2. I purchased an inverter with a completely different part number that an ebay seller listed as compatible with the Dell Inspiron 4150, #J07i037.05, and it appears to be working perfectly except that it has a few extra holes for screws. Should I be concerned about using a different inverter than the exact same as the old one????
August 29th, 2007 at 1:46 am
August 26th, 2007 at 4:14 am
I have a compaq armada e500 with a defective inverter, 15,1″ I also have al working compaq armada m700 14,1″ screen witch is compatible they tell me
Can I use that inverter for the defective screen ?
2de question I have removed al the screws of the 15,1 screen (4 screws) 2 at the lock 2 at the bottom corners but I can’t remove the front.
What I’m I doing wrong ?
August 25th, 2007 at 5:43 am
Thank you for your site. I have found here much useful information.
Good site !
August 20th, 2007 at 12:21 pm
THanks…I had a ze4900 which had a lcd flicker problem…..just disassembling and reseating fixed the issue.
The detailed instructions and photos here were a great help in giving me an idea of how to do this.
Thanks a lot!
August 18th, 2007 at 10:26 pm
caleb durward,
The screen has a reddish hue on start up or it’s solid red color? When the screen has a reddish hue, it might indicate a problem with the backlight lamp. Here’s a example of replacing the backlight lamp on an IBM laptop. It’s possible but not easy.
I think replacing the laptop screen through Dell might cost you a fortune. You can find a used screen here for $100.
August 18th, 2007 at 10:13 pm
BHAGWAN DAS,
1. bad connection between the cable and the inverter board. Try reconnecting the cable
2. bad inverter
3. dead backlight lamp (CCFL tube)
August 18th, 2007 at 9:36 am
Hey again, sorry about the double post, just read through all of the previous comments. I re-checked all of the connections and the lid-button-thingy and it’s all fine. The screen flickers red at the very start and then goes dim, and since I replaced the inverter (twice!) I guess that means the problem is in the light itself, but you guys don’t seem to reccomend trying to replace it. Still, what if the Dell guys just want to replace the whole screen? If they’re going to replace it anyway then who cares if I might damage it attempting to replace the backlight lamp? Or is there some other expensive thing that I’d need to watch out for? -Not intimidated by soldering.
Thanks for all the help this site has given, it is very much appreciated!