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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August 30th, 2010 at 5:39 am
Hi, I think my problem may be a loose cable or the inverter board. Its a g71gx from BestBuy. Ive been getting white flickering time to time: other than that- the picture is fine. I don’t get flickering when I don’t bother the screen at all when I leave it up. But even now: I’m getting a little flicker time to time. Not as bad when I move the screen. I’ve reinstall drivers, driver sweeped, and everything. I believe this is a hardware problem.
Since I bought it from bestbuy a little than a year aago..I’m not sure if I have Asus’s 2 year warranty..Help please?
August 24th, 2010 at 8:15 am
Paul,
1. This is not related to the inverter board, that’s for sure. You still can see the screen, so the backlight/inverter work properly.
2. Test your laptop with an external monitor and take a closer look at the external video.
If external video has same static problem, probably you have failing video card.
If external video works properly and the problem appears ONLY on the laptop screen, it’s not related motherboard/video card.
Again, if this problem appears only on the laptop screen, it’s not motherboard. Most likely it’s either video cable or LCD screen problem.
1. Try reconnecting the video cable on both ends. Make sure the video cable makes good connection with the LCD screen and motherboard (video card).
2. Take apart the display panel and try moving the video cable while the laptop is turned on. If moving the cable affects image on the screen, maybe it’s getting better or worse, probably you have a bad cable. Try replacing the cable.
If moving the cable doesn’t affect video on the screen at all and the image always has the same static, probably this is LCD screen failure. Try replacing the screen.
August 23rd, 2010 at 10:35 am
Hi,
I’m trying to fix my vostro 1500 with a similar issue.
There is a purple haze, as well as some static, over all of the menu bars in windows/firefox/etc. It’s very annoying. Also, on the windows startup screen there is a very curious looking white ring that kind of pulsates with static:
http://img819.imageshack.us/im.....g0104k.jpg
I’ve done a system restore, reinstalled video and bios drivers, opened the laptop and jiggled the lcd cables to see if there is a break, blown dust off the motherboard, all to no avail.
To my knowledge, there are three culprits left: lcd, inverter, or motherboard. I have my suspicions, but if anyone can offer any advice please do.
Thanks!
August 13th, 2010 at 5:38 pm
Very informative information..thanks for posting you all, keep up the gr8 wrk
July 31st, 2010 at 6:51 am
Great and helpful post. I tried to repair the display on my HP ze2000 but need some more help.
Problem: The display is too dim and hardly visible. When connected to an external monitor it works very well.
Based on this and similar articles, I figured it is the inverter. So I purchased an inverter from ebay and replaced it. Again same problem. Then I thought it must be the backlight. Since I could not find it easy and safe to get to the backlight, I purchased the LCD screen, hoping this would definitely solve it. Still same problem. Exactly as it was in the beginning. Can anyone help?
July 29th, 2010 at 9:54 pm
birendra,
Yes, in some cases this problem is related to the inverter board failure, but sometimes it could be related to the backlight lamp, video cable, lid close switch or even motherboard.
Anyway, try replacing the inverter board first.
You can get manuals for HP, Dell, IBM/Lenovo laptops but not for Toshiba, Sony, Acer, etc…
July 29th, 2010 at 5:21 pm
Any problem taken to a professional will cost you immense amount of money. Be it a simple visit to a doctor with fever or to a mechanic for just a brake problem. First they will try to test you with 20,000 other things which are not necessary just to jack up the price.
If you have a dim light on your laptop screen more or less its sole culprit is the inverter it self.
The part it self costs around 50 dollars. and you dont have to be a computer savvy person to do it.
Thing to do:
1) Go to manufacturers website and download the manual for your laptop.
2) There you will usually find the spare part number for your inverter.
3) Once you get your part, unplug the power cable and remove your battery once you shut your computer.
4) press the power computer(that is to remove any static energy that is still stored in the computer)
5) Ground your self by touching some metal or using the strap.
6) Find the screws in the screen and unscrew them.
7) Find the inverter wrapped in a plastic covering. remove it but dont throw that plastic covering since you will reuse it.
9) leave it for 30 more minutes just to see its working properly
July 28th, 2010 at 9:16 am
I am facing exact same problem i.e. my IBM R50e laptop screen has gone blank but I am able to use additional screen (desktop) and managing my work. Kindly let me know how much does it cost to replace that inverter as I am not sure if I should repair or get a new laptop instead.
Thanks in advance.
Regards,
Abhijeet
July 25th, 2010 at 5:17 am
hi. my laptop is having some problems. when i turn it on there is the baclight and some sort of flashing as it boots on the screen by it does not display anything.what could be the problem. please help