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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October 24th, 2008 at 6:47 pm
I got the same problem guys but i don’t think it’s a bad inverter, but it may have led me to the correct direction. My backlight bulb fails to light up, but that doesn’t mean the bulb is bad, because sometimes it does light up. My screen goes very very dim, then i have to slightly close the computer lip…. to decrease the angle, then it will light up, then i increase the angle and it’s gone. Sort of a chance by chance thing. Im figuring it’s bad connections or loose connections, so I’m going to take off the lid and check it out.
October 23rd, 2008 at 10:51 am
i have the same problem as mentioned with my R50 Think Pad IBM here but what should i do or where their a place to fix these kind of a problems?
i’m not so familiar with opening the screen or what ever it would be is there any one might checking the option within my area?
90048 los angeles
October 22nd, 2008 at 7:32 am
Lol i have that exact part
3 of them in fact except i believe that two are broken
October 21st, 2008 at 2:01 pm
Hello, My laptop screen started trembling (flickering) I opened my laptop screen and found this inverter
71-4200R-D02
http://www.clevoweb.co.uk/Parts/71-4200R-D02.htm
When I wiggle it with a plastic pen it shows some trembling but I cant find exactly a position that stops the trembling of the light…
Does anyone know of a place in europe that has this for a cheap price? How much does these cost normally? I am in Greece.
Is there any way to REPAIR an FLinverter?
October 21st, 2008 at 11:33 am
Awesome, your hint of the close lid switch was the answer in my case. KUDOS to you for the hint.
October 20th, 2008 at 6:57 am
you rock! this totally explains my problem (i need an inverter). i now can confidently arrange repair. thank you!
October 17th, 2008 at 12:41 pm
Hi All,
I am having trouble with my Thinkpad T42 LCD screen. The problem almost perfectly fits the symptoms of a bad inverter (backlight is off, but an unlit image is still formed on the screen; backlight comes on briefly if I open and close the lid). However, I replaced the inverter, and the problem was not resolved. There is one other symptom (I think): when I open and close the lid, and the backlight turns on briefly, the color on the screen is wrong (the white-point is off, and everything has a red tinge). Does this suggest any other cause for my problem than the inverter? What other problem fits these symptoms (especially that the backlight turns on briefly when opening the lid)? This doesn’t seem to me like a problem with the CFL bulb, but maybe I’m wrong.
Thanks for your help and insight!!!
Steve
October 17th, 2008 at 9:51 am
Hi I am replacing a lcd screen from sreentek of my alienware aria 51-m m5500 series a 15.4 b154ew08 v.1,the screen only show 1/4 of it on the left side of the screen the right part has different shade of blue line from top to bottom i change the lcd same thing
but if i plug my desktop lcd monitor the loptop works fine and i also change lcd cable (new) same result, could give an advice
maybe its the video card?
thanks.
joey
October 16th, 2008 at 7:20 pm
I’m trying to diagnose a Dell 6000. The screen lights just for a second on power up, then it remains dark. Sometimes it is very, very faint, but usually it’s completely black. Could this be the inverter board?
October 12th, 2008 at 4:31 pm
Jasper Pollet,
Apparently, you have the same problem as Gerard Verbeek – failed backlight lamp.
If you cannot replace the backlight lamp, you’ll have to replace the whole LCD screen.
Maybe you can find a technician who can replace the backlight lamp for you.