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 … 24 23 22 21 20 [19] 18 17 16 15 14 … 1 » Show All
October 13th, 2007 at 7:38 pm
Richard Lewandowski,
What do you mean they cannot fix it even with extended warranty. If the laptop is still covered by the warranty, they should fix it. If they cannot fix, they should replace the laptop. This is the main purpose of the warranty.
Most likely you cannot find this utility on the HP website because it’s available only for authorized repair centers. You purchased another motherboard from eBay and probably this is a used motherboard. There is a good chance that you don’t have to reprogram the motherboard because it had been programmed already and it will work as is.
October 11th, 2007 at 9:17 pm
Hello: I’ve been tinkering with laptops for only a short time now so my cousin gave me a dead one (HP ze5375) which no one would fix even with an expensive extended warranty. It turned out to be the notorious power connector problem. I bought another motherboard on eBay and I am in the process of putting it back together slowly but my main concern is the note in the service manual that after replacing the motherboard I must reprogram the EEPROM on the motherboard for the new display. Is this going to be a problem? I can”t find any info on the HP website that the manual refers to as the Partnership Web site. Thank you
October 5th, 2007 at 11:42 am
Cheryl,
Make sure the LCD lid close switch is not stuck inside the case, it should move freely. If parts you installed into the laptop were good, then the next logical step would be replacing the video cable and finally the motherboard (or video card if it’s a separate module). I don’t know what else to blame.
Not sure if refilling the battery is a good way to go, never done it before myself. Unfortunately you cannot tell if refilling the battery worked well, at least I don’t know a good way of testing the battery beside charging it in another working laptop. You’ll have to test your laptop with another KNOWN GOOD working battery. If it fails too, you have a problem with the motherboard.
October 5th, 2007 at 9:27 am
Hey-
WOW! Your disassembly instructions are GREAT. I came across your website after searching for a resolution for my wife’s R50. Similar problem to what alot of others have; no backlight. The image is there on the LCD, but it’s dark (that would be the definition of no backlight!) External monitor works fine. So I bought a new inverter card and replaced it. It was a drop ship from IBM, so I’m fairly sure it’s good. And the LCD still has no backlight. ARGH. I have not had a chance to check the output voltage, but I’m going to /assume/ it’s OK. One thing to note, when I turned on the computer after replacing the inverter, I heard a hissing from the bottom left of the screen. It sounded like a gas charging (or discharging). Any thoughts? What would the next step be? Do I replace the backlight? Any recommendations on where to get that?
Thanks!
PS: The same computer has similar battery problem as Cheryl; I’ve written it off to the short discharge cycle my wife was doing. She would only use it on battery for 30 to 60 minutes at a time.
October 4th, 2007 at 3:30 am
PS… we did replace the powerjack. (that was while the battery was away being refilled and before I did anywork on the lcd problem, as I thought It may solve all the problems). Thank you.
October 4th, 2007 at 3:27 am
Hi, Thank you for your help. I did go ahead and replace the backlight. I was very careful and guess what… It didn’t work. SO just to quickly review, I replaced the backlight, and the inverter, I am at a loss. Still get an image on the screen but very, very dim. I am viewing the screen on an external monitor. The company selling the inverter is sure it was a working one. (But found out it was harvested). But I think I will go ahead and resolder the light just to make sure. I don’t know, I am grasping at straws. On the battery, I haven’t found the pattern in the problem, but here is the background. The battery life was gettig quite short, but the laptop was purchased in 2003. SO just thought it was the battery life. We started having powerjack problems and the battery would only work for minutes at a time. I chalked it up to being an old battery. I went the route of having it refilled. Now the Battery LED light may come on for a sec. but goes out immediately. The computer will not run on the battery at all. Originally the power meter in windows had 0% charged and showed the batteries ID information, also it said it was online and charging. BUT when looking at the power meter without the battery installed. IT gives basic information of a Bat1 Battery and says it is online and charging. I tried refreshing it by going into safe mode and unplugging the Adapter. THe computer shuts right off. It doesn’t seem to recognize the battery is there to draw from. Anyway. After doing that the first time, I left the Laptop plugged in, No charging light, and the next day we were at 47% according to windows power meter. Since then it is down to 46% and holding, the Laptop still will not run on the battery and I can’t seem to get it to charge anymore even by going in to the safemode. ALSO, the show power meter on taskbar check box was checked, but it was not showing. Simply unchecked, clicked apply and rechecked and applied and it did appear. But still can not use the battery. Lastly, I get a very short flash of lights when trying to start the laptop on the battery. Almost unnoticable. If you have any ideas, I would greatly appreciate it. Sorry for my long winded explanation. Thanks again. CHeryl
October 1st, 2007 at 10:51 am
My screen stays black on the IBM x31 screen. I checked the lamps (working fine) and put a new inverter but I still can;t see anything on the screen (but shadows).
With an external monitorl everything works fine.
September 30th, 2007 at 8:37 pm
Cheryl,
In most cases, if you can get video on the external monitor, there is nothing wrong with the motherboard or video card.
There is no simple answer to this question. What kind of problem you are experiencing with the battery? Usually, to find out witch one is causing the problem the battery or the motherboard you’ll have to test the laptop with another good working battery.
September 29th, 2007 at 2:00 pm
I am going to replace the backlight. It is in the mail. for $14 we thought we would give it a try. Hubby has more faith in me than I do. I wonder though. You mentioned the motherboard. May I ask a further question on that topic? I am using an external monitor from my desktop right now and I see the picture great. Would I be able to use this monitor if the problem was the motherboard? or are they 2 separate things. am having trouble with my battery and wondering if it is the motherboard. … Hence my question. THank you again.
Cheryl
September 28th, 2007 at 7:59 am
I am going to replace the inverter for a second time, i will repost and let you guys know how it goes.