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 … 26 25 24 23 22 [21] 20 19 18 17 16 … 1 » Show All
December 27th, 2007 at 12:21 am
James,
Did you test the laptop with an external screen? The external video goes off too or it works fine even though the laptop LCD went blank?
December 27th, 2007 at 12:18 am
Kyle,
Looks like you’ve replaced everything that could be related to this problem.
Here’s one more thing you can try. Did you check the lid close switch? It’s a small button located close to the left hinge. This button turns off the backlight when the display is closed. It’s possible that the lid close switch got stuck inside the case and because of that the power never gets to the backlight lamp. Make sure the lid close switch moves freely, without any problem. Try tapping on the lid close switch when the laptop is running and see if it makes any difference.
December 26th, 2007 at 3:46 am
I have an IBM T41 which now starts to show symptoms of complete screen blanking. No shadowing or faint items can be seen on the screen, the screen just goes off. After the notebook is switched off after a while, it powers up fine but then reverts back to the display going completely blank. I have turned off ALL the screensavers, power save options etc etc but to no avail!
December 24th, 2007 at 9:44 am
Laptop Repair,
I have some of the same symptoms as people mention on here and still haven’t been able to pinpoint my problem. Any help would be appreciated. Here are the symptoms and what I’ve done so far.
My LCD on my IBM went black one day while it was booting. The color was always great until the last day so there were no symptoms of a fading bulb. It happened all of the sudden. I can still see everything on the screen with a flashlight but it’s not bright. I can hook it up to an external monitor use the computer fine that way so I think the graphics card is ok.
I then bought a new inverter card from IBM thinking it would be a quick and easy fix that were the problem. I swapped them out, made sure the connections were good, and still the same problem. I can see everything, but it’s not bright.
Then I ordered a new bulb and attempted to replace my bulb on my own. I soldered the new bulb to the leads and tested it with the new inverter. It never lit up. So I thought I damaged the bulb when I tried to repair it.
Then I thought it could be a setting in windows. So I went into the display properties and noticed that my LCD monitor was shut off. I turned it on, applied settings, hit ok and then switched to the LCD output and still had the same result. It had picture but just very dull. Adjusting the brightness didn’t do anything either.
I then bought a used replacement LCD on Ebay and hooked it up with the new and old inverter card, new one first, then had the same problem even with that monitor. Picture but not bright!
I think the inverter card should be ok because it’s new, the LEDs light up, and all the connections are good. I think it’s unlikely that my old LCD, new bulb and used LCD are all bad. One of those bulbs should have lit up with the new inverter card.
Could it be something with the graphics card? BIOS? Display Driver? I did a fresh install of the recovery CDs containing windows 2000 pro. It restores the system to the factory settings. I still get the same output. What is going on here?
Thank you,
Kyle
December 23rd, 2007 at 4:04 pm
Dave,
If the power jack has come loose you’ll have to resolder it. Here are instructions for replacing or resoldering the laptop DC-IN power jack. Check out HP service manual for your laptop, usually HP includes disassembly instructions in the manual. It might help removing the motherboard.
December 18th, 2007 at 6:29 pm
I have a HP Pavilion ze5300 with a power jack that has come loose. I’ve been able to use the laptop by toggling the cable a little whenever I get a power message, but it is getting worse. Is this something that I can repair myself?
I have been quoted about $200 for labor and parts, but online I see that this part is just under $4.00.
My biggest concern is opening up the laptop without breaking anything. Is there a resource where I can get instructions on taking apart my specific laptop? Thanks!
December 15th, 2007 at 10:29 am
201 (Tatsat)
eBay is where I bought my inverter from.
Serarch for “HP Omibook Inverters”.
You may want to check the exact number on your inverter, as it states in the last picture of this article, to make sure you buy the correct one.
December 15th, 2007 at 10:26 am
Hi,
Last week, my Dell 6000’s screen went dim all of a sudden. After some Google research, I found this website and decided that the problem was the LCD Inverter. The screen was very dim, though I could still make out some images and an external monitor worked perfectly.
I found one on eBay and ordered it. Once it arrived, I installed it which took about 15 minutes. I turned the computer on and everything worked fine again. So, I put the computer back together and turned it on. The screen was dim again. I turned it off and turned it back on.
The laptop then worked perfectly again, with a bright screen. But, I heard a high pitched squeal coming from the bottom of the monitor. I determined, through more Google research, that it was the inverter again.
I’m not sure if I simply installed it incorrectly, which seems unlikely since it does work, or if there is something wrong with the power source. The battery on this laptop is quite old and does not hold a charge for longer than an hour anymore. There are constantly orange blinking lights, which signifies this, according to more Google research.
Is there any way to subdue the squealing noise without buying another new inverter, or is the problem a bulb?
I have been running my laptop on the dimmest setting, since the highest setting makes the squealing noise. Actually, I just raised the setting, and the screen is now dim again.
I saved this post to a text document (barely seeing what I was doing) and restarted the computer. Now, it’s working again on the dimmest setting.
Please help.
Regards,
~Scott
Internapse.com
December 13th, 2007 at 2:07 pm
I have Dell 8600 laptop. All of a suuden my screen gone very dim.its working with the external monitor though. based on the comments of the people on this blog i replaced the inverter but the problem is still the same. I am not sure what to do next..please advise.
December 12th, 2007 at 9:26 am
I have HP omnibook xt6200 laptop, yday suddenly my screen gone,so I restarted manually. It started all in normal but screen is very dim i can barely see Images,logging process and everything. according to above posts I think its may screen inverter broken?
can anybody suggest how can I find the compatible Inverter for my laptop model.
Thanks in advance..really very useful forum and website.