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.
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March 29th, 2007 at 7:00 pm
My problem is a little different from all of these, as my screen does not go out completely, but I still have problems with it. The color on my screen is not as bright as it once was, and fluctuates between being brighter and dimmer. I can deal with that, as it stil works, but not the colors on my screen are all inverteted! As in, black is white, orange is blue… it’s driving me crazy! Any suggestions about where to look to fix it, or just what on earth is wrong with it?
Thanks!
March 26th, 2007 at 5:39 am
58Howard Lewis Says:
March 23rd, 2007 at 7:50 am
I have installed a NEW inverter – which did not help. I’m beginning to think it may be the back light. I can’t see any picture at all except on an external monitor. Any one agree OR disagree ???
I could use some help diagnosing this.
Thanks
Hi, I tried two used inverters in my IBM T21 , I see the screen very very vague so I also think it is the backlight itself, does anyone have a solution?
TX, Joe
March 26th, 2007 at 1:15 am
My laptop is not showing anything on the LCD, its black but it can turn on when i switch it on. Pls help me
March 23rd, 2007 at 8:36 am
i have the solution to all the person who cannot find the inverter for the quanta display lk01 of 15.4 wxga 1V11145/T,
http://www.impactcomputers.com/iv11145-t-.html I HOPE THIS WORKS FOR YOU
March 23rd, 2007 at 7:50 am
I have installed a NEW inverter – which did not help. I’m beginning to think it may be the back light. I can’t see any picture at all except on an external monitor. Any one agree OR disagree ???
I could use some help diagnosing this.
Thanks
March 22nd, 2007 at 6:21 pm
Ram Mohan,
the laptop screen might turn completely white (on some models) if you unplug the video cable from the LCD. It is possible that in your case the video cable is loose and needs to be reseated. Unfortunately it’s necessary to open up the display assembly, get under the screen and reseat the video cable.
March 22nd, 2007 at 5:23 pm
Jorge Trevino,
Try here. Enter “Laptop model inverter” and see what search brings to you.
March 22nd, 2007 at 3:39 pm
I have a monitor problem with a Compaq Presario R-4000 with a 15.4 screen I need to diagnose. Any help will be appreciated. My screen is black – cannot see any picture, but works perfectly with external monitor. I tried a new inverter, but it did nothing. Anyone have suggestions – PLEASE !
Thanks,
Howard Lewis
March 21st, 2007 at 1:52 pm
Hi:
My NEC Rugged PC (FC-11) screen goes White when it is fully opened (over 45 degrees). However, when I close it to less then 45 degrees, the screen comes back up. How can I fix this?
March 21st, 2007 at 6:22 am
Ok I remove the inverter from the laptop, now where I get the replacement is quanta display is a 15.4 wxga I call dell they dont sell the part separate, what I can do? anybody have any advice where I can get it