Screen inverter replacement. Fixing laptop backlight problem.
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.
Entry Filed under: Replacing Screen Inverter
311 Responses to “Screen inverter replacement. Fixing laptop backlight problem.”
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Pages: « 32 31 30 29 28 [27] 26 25 24 23 22 … 1 » Show All
May 31st, 2008 at 7:48 pm
Martha,
This problem is related either to the inverter board (most likely) or you have bad backlight lamp inside the screen (less likely). I would try replacing the inverter board first. You’ll have to use inverter designed for your laptop.
Yes, you can if this is the same or similar model.
You can find the HP part number on the inverter board. Find the part number and then google it.
May 31st, 2008 at 7:41 pm
James Clarke,
I think on some Dell laptops you can adjust the screen brightness for both battery and AC modes in the BIOS. Enter the BIOS setup menu and lower the LCD screen brightness for the AC mode, so it’s the same as for the battery mode. Hopefully it will fix your problem for a while.
May 29th, 2008 at 8:32 am
i got an ibm thinkpad laptop and recently dropped it and luckily only cracked the casing does anybody know where i can a spare casing for it as its affected the screen clips
May 29th, 2008 at 3:43 am
I have an HP Pavillion xz295. The computer boots up and i can see a faint image it is so dim it looks as if it is black. Is this still a problem with the inverter? If so, could I use a inverter from another laptop? Or does it have to be from the some make and model. If I need to purchase a new one, can I purchase one in a store near me or does it have to be online?
May 26th, 2008 at 12:02 am
Hi, I am trying to diagnose an inverter problem on a 15.4″ Dell Inspiron 6000 Laptop. The screen switches off at full brightness but works fine on anything below full. So when using the laptop with the charger in i get a black screen without just a slighty dimmer one.
Cheers
Jim Clarke
May 22nd, 2008 at 11:37 am
I HAVE THE ISSUE, JUST GOT NEW SCREEN, BLUE HUE, VERT LINES STILL. FOUND THE ISSUE WITH CABLE. WIRE BROKE INSIDE, MAKING CONNECTION IF MOVED BUT AT FREE STATE I HAVE THE ISSUE. ELECTRONICS TEACHER PULLED THIS MOVE ON ME IN CLASS. PULLED WIRE OUT OF COVERING. CUT INTO PUT BOTH PIECES BACK IN, WOULD WORK TELL YOU MOVED WIRE, THEN NOTHING. HOPE THIS HELPS
May 20th, 2008 at 4:40 pm
I had an older T42p with out a burned out motherboard. Pulled the inverter and popped it into my newer T42p with non-working backlight, and now it’s working again. Excellent! Only took about thirty minutes to make the swap (due to your instructions).
May 18th, 2008 at 10:31 pm
marc robert,
Yes, this could be connection related issue. Try to reseat the video cable connector on the motherboard first. You can easily access this connector if you remove the keyboard bezel. I posted Satellite P30/P35 disassembly instructions at www.irisvista.com/tech/
After that you can try reseating connection on the back of the LCD screen. You can use instructions for a Satellite P25 display disassembly.
Proceed on your own risk and do it only if you feel comfortable taking apart your laptop.
May 18th, 2008 at 10:19 pm
Casey,
You are right, most likely this is related to the inverter board. How much for a new inverter? It depends on witch laptop model you have.
Take a look at the inverter board. Find the part number and google it.
May 18th, 2008 at 10:14 pm
JT,
Did you test your laptop with an external monitor? The external video goes blank too?
Did you try upgrading the BIOS to the latest version? For example, Toshiba Satellite A215 has a similar issue when LCD screen goes blank intermittently. Toshiba supposedly fixed this issue in the latest BIOS release.