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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March 10th, 2007 at 9:28 am
Reger Wells,
I’m not sure if this is an inverter problem. When inverter goes bad you loose ALL backlight, not just 2/3 of it.
March 10th, 2007 at 9:07 am
Kenny,
Search for “Dell C610 inverter” or “Dell C640 inverter” here and find one you need.
March 7th, 2007 at 2:29 am
HI THERE
I HAVE A LAPTOP OF SONY..THE PROBLEM I AM HAVING IS WHEN I SWITCH ON THE SCREEN IS TURNING TO WHITE COLOR .PLS TELL ME WHAT IS THE WRONG WITH MY LP
March 6th, 2007 at 9:41 pm
My laptop screen will go very dim, then cutting the monitor off or forcing it to go into standby mode will make it come back on for 15 or 20 seconds then it goes back out again.
However if the power cord is not connected to the computer, it works fine. Is this still the inverter or is it something else?
March 6th, 2007 at 3:17 pm
I have a Toshiba satellite 1135. It usually sits on the counter running through it’s photo screen saver. One minute it was on like normal the next minute “black”. I flipped the cover switch and it momentarly goes on for a second, but it was in a “red” cast – no other color and then black out again. I plugged my regular screen into the laptop’s jack and the stand alone monitor worked fine. The laptop is 5 years old. Should I replace the back light as well? or is the inverter the cause? Thanks for any help you can give me.
March 6th, 2007 at 7:42 am
I have a TP X31. Yesterday the PC died as though something overheated. It came back after 20 minutes or so. When it restarted the display is dim, not black just about 1/3 as bright as before. It is now working with a dim display but is usable. Would the inverter be the suspect component?
March 4th, 2007 at 10:51 pm
Thanks! for this very helpful information, you are a money saver thanks.
March 4th, 2007 at 9:01 pm
I have a Dell Latitude C610 display screen on my C640. Its been working fine until the inverter went bad. I want to replace it and have already taken it apart, but I dont know what to use to find the replacement part because it doesnt have a tag on it like the one in your guide. Do you know where I could find the part number for it or do you happen to know? Thanks.
March 3rd, 2007 at 9:02 pm
Carmen L,
Here’s a picture of the inverter board for a Dell Latitude Cpx notebook.
http://www.asklaptopfreak.com/.....verter.jpg
Isn’t it located somewhere inside the LCD panel? By the way, you can find a new inverter for about $6 on eBay.
March 3rd, 2007 at 12:01 pm
I don’t find the inverter on my screen. I have a Dell Latitude Cpx. Can anyone please tell where it at? Thank you.