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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January 8th, 2009 at 8:23 am
Hi there!
I Have Dell laptop INSPIRON 6400 for last 3 years and recently I have problem with monitor. No image on it only vertical lanes, back light working ok so screen looked to be white. I connected external monitor and laptop works ok, so I replace screen and that didn’t fix problem then I replace video cable and still no joy, at this stage I’m running out of ideas, didn’t try replace inverter back light working ok so I don’t its inerter can inverter effect image on lcd? Any chance you can help me my warranty expired, please help Val
January 7th, 2009 at 12:08 pm
yes. exactly the same. now i see it’s a bad LCD screen.
Thanks!
January 7th, 2009 at 10:14 am
shawn,
If the screen still lights up there is nothing wrong with the inverter or backlight.
Does it look like a screen in this guide? Removing LCD from HP dv6000
If it does, most likely it’s a bad LCD screen.
January 7th, 2009 at 10:11 am
Aashtee,
It’s hard to tell until you test the laptop with another working inverter board. Could be either bad inverter or failing backlight lamp.
Here’s something to try. Enter the power management utility and lower LCD brightness for the AC mode, make it the same as for the battery mode. It’s possible after that you’ll be able to use your laptop with AC adapter too.
Be careful with the LCD mask, it’s made of fragile plastic. Do not forget to remove the battery. And do not hurry.
You should check the FRU part number on your inverter and buy the same.
January 7th, 2009 at 9:49 am
my T60, the top 1/3 of the display works fine, but the bottom 2/3 is full spectrum colorful tiny verticle bars. what’s the problem? inverter? backlight? or something else? please help me with this!
January 3rd, 2009 at 5:17 pm
I am so glad to have found the root cause of my problem.
I still need some further help before i go and open up the LCD to get the FR number to buy a new inverter.
1. My laptop LCD works fine on battery power (Its much less bright than ii used to be and compared to my husbands T43. But at least i can use the laptop for the 30-40 min it works on full charge! The minute I plug in the AC power it flickers and turn off but I can see the image is there. Is this still an inverter problem?.
2. I know the process seems simple with the pics and all but is there any special care I need to take to ensure I do not mess something else up when i replace the inverter?
3. Is it possible to use the same FR number and buy an inverter card before i open up my laptop?
January 2nd, 2009 at 12:12 pm
hi
thank you for your valuable information on laptop.
i have a Sony notebook vgn model. the laptop shows half screen when i poweron but the bottom screen images are not visible.
i connected the laptop with desktop pc (dual monitor setup) it works fine..
i have a doubt , the trouble is because of invertor or screen ?
can you please help me in this issue/
gk
December 26th, 2008 at 4:37 pm
i have a compaq laptop with a 15.4 brightview lscreen that has a glich or something going on with only the bottom third of the screen. if i put pressure on the lower left hand side of the screen it will look ok till i let it go. it seems to be getting worse. i have opened it up and checked all the wires and i checked the screen for damage. all seems well and i have never dropped the computer. any ideas? do i need a new screen? inverter? video card? i donno? ill appriate any and all help and info you come up with.
thanks
December 26th, 2008 at 3:12 am
Can someone help me with freezing VGN-FE41M.
Sometimes my laptop freeze at startup and sometimes when working on windows Vista or XP. I have check all components like memory, HD, Modem, NIC and replaced them by others but nothing helps. Vista and XP have installed many times too.
Does anyone have any idea what the problem is?
Thanks for your help.
December 24th, 2008 at 9:08 am
Help with Thinkpad T41. Have an IBM Thinkpad T41 that has a disk problem. The laptop randomly just goes dead. Its not a power source issue, but seems to be a problem with the disk drive. With constant medium pressure on the keyboard, directly above where the disk drive sits, the laptop will run without a problem, while a bit awkward to use (lol). However, remove the pressure, and the system stops instantly. I’ve reseated the drive a couple of times, without any luck. Am trying to determine if there’s some known issue, or how best to diagnose / resolve. This is an older refurbished unit. Thanks for any help.