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!
January 26th, 2009 at 11:10 am
Thanks for putting out this excellent guide. I was able to replace the inverter on my dell inspiron 5150 using the procedure provided. Couldn’t have done without it. Thanks Again!
January 24th, 2009 at 2:43 pm
Before I pitch this thing:
I have an hp dv1720us. The inverter went out once and hp repaired under warranty. It seemed to go out again – classic description – at bootup see logo then goes dim. I ordered replacement, put in, worked for 24 hours then stopped. Same scenario. I ordered replacement and no go.
What is interesting is that connector to the left, facing machine, the one with 4 or 5 little connections – if I “wiggle’ it, or just barely attach, the display comes on but then goes again – almost like it’s a short or something but I can’t figure how to troubleshoot it. I’m just about going to give up and sell it for parts on ebay as I don’t want to spend money on it.
If there are any words of wisdom, please let me know.
Thanks in advance.
January 24th, 2009 at 11:03 am
Its a Compaq v5000 the screen went black and all you can see is lines running up and down if i move the screen it will get brighter and some thing could me seen at times but only for a second. could it be the inverter of the screen
thanks in advance.
January 22nd, 2009 at 7:38 pm
Dell Inspiron 1720: The screen went dark on the left side but is fine on the right side. What would cause this problem? Looks like the backlight is out on the left side only — is that possible? I can read the left side of the screen, but it is darker that the right side.
January 21st, 2009 at 3:02 pm
I have a problem I’ve replace it but it seems no only partially work!
I orders a hp dv1000 LCD inverter and it fixed the dim problem.
But when I unplug my laptop and run of the battery its all dim again.
I thought it might be a defective product from the manufacturer,
so I ordered another one and its still the same thing..
Its really weird…
Plugged into the wall, electricity, it works fine
Running off the battery its back to dim barley seen screen.
Please advise.
I also would like to know how I can tighten my screen cause unlike other laptops the hp dv 1000 dosent have a simple screw that I can just tighten
Thank you
January 21st, 2009 at 10:50 am
DUDE I LOVE YOU! Tapping the button fixed my monitor on my laptop THANK YOU SO MUCH!
January 20th, 2009 at 2:35 pm
Just replaced a laptop screen… random horizontal lines at random times. Nothing seemed to cause it, just appeared randomly. Twisting the screen, or torquing the screen fixed the problem for a short period of time. Turned out to be the screen itself.
January 19th, 2009 at 10:07 pm
hello.
i have a toshiba satellite a135-s4467. its 2 years old and my display went dim. i replaced the fl inverter today, and the computer was running great. however, i thought i should mention that when i replaced the inverter, it was buzzing a bit. i was fearful at first but then the buzzing stopped. my joy was short lived though, after approx 3 hours or so, the screen went dim again. same prob. that i had before. display visible with a flashlight…..
was wondering if i received a bad inverter, or is something else causing the inverter to go bad. this computer obviously is out of warranty and i’m in no situation right now to purchase a new one. so i was trying to fix the problem myself.
can anyone tell me if something else can cause the inverter to go bad
January 18th, 2009 at 2:23 pm
Dell Vostro 1000
Display is much dimmer than normal, but not totally dim as I’ve seen on other laptops with a bad inverter board.
Do you think this is also a bad inverter board? I’m going to replace it to find out, but am curious.
January 16th, 2009 at 5:32 pm
Inspiron 6000
laptop very dim. can see the screen faintly in well lit room.
i replaced the inverter but it doesn’t fit perfectly. the screen holes don’t line up exactly. but the connectors fit fine and i just used a bit of tape.
is the screw necessary for an electrical connection? can i drop some solder to connect them?
do you think the lamp is broke?
thanks.