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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April 9th, 2007 at 6:30 pm
Jacin,
Most likely it’s just a bad inverter board and your diagnosis is correct.
If you can find a new screen and lid just for $200, I would go with that. Replacing the backlight lamp is not an easy repair.
April 9th, 2007 at 6:22 am
It would appear that my inverter went out last night but, now that I’ve already gone ahead and purchased a new one and disassembled my laptop, I wanted to post here and ask for a ’second opinion’.
Here’s the situation: I’ve got an HP Pavilion ze5300 series laptop. Last night, I was working on it doing some graphics work and the screen went dark. I could still see some of what was there, but it was extraordinarily dim (though, this morning, nothing is visible at all).
So, after some quick research via Google, I went on eBay and found what I thought I needed (a new inverter) and it should be shipping out tomorrow.
Am I correct in thinking that is that the correct repair … ? If it’s not, is the cold-cathode flourescent bulb something I can fix on my own, or would it be better just to order a new screen and lid for ~$200.00 … ?
Thanks for the assistance!
April 8th, 2007 at 11:07 pm
Jeff,
Yep, looks like a classic inverter problem. I think your diagnosis is (was) correct and I would replace the inverter board in this case too.
I’m not sure why the screen went dark. Did you use a correct inverter board?
You’ll have to find another inverter board or find a test backlight lamp.
April 8th, 2007 at 9:51 pm
Rachel,
Search for “Gateway 400VTX inverter” here and you should be able to find it. I would recommend contacting the seller and ask him about any compatibility issues, just to make sure you are buying a correct one.
April 6th, 2007 at 8:18 pm
I had an issue that seemed like a classic inverter problem. The screen was still visible, just without a backlight, it worked with an external monitor, and when I pressed the screen closed button, it would flicker on for sometimes 5 seconds and sometimes an hour. Also, the top of the laptop is cracked (not the screen, but the plastic casing) just from general use.
I found a new inverter on ebay and put it in and had no change. Then, a day later, the screen lit up brightly with an audible “pop” and went dark (no backlight but still a dim LCD image) and hasn’t come on since. My best guess is that there was a short somewhere in the backlight circuit that blew this inverter and might have blown the bulb too.
So, my questions to the group are: 1) Does my diagnosis seem correct? 2) How difficult would this be to track down and fix myself without breaking something else (like the LCD)? and 3) Would I be better off just ponying up the $400 for a new display, which I’m sure I could install myself, since the current casing is cracked and the repair might be that much anyway?
April 6th, 2007 at 2:27 pm
I have an HP dv1000. inverter board was bad but when I replaced it, it only worked with the battery, not when plugged in. got 2nd inverter board and replaced it today. it works with both battery or power cord BUT if laptop is powered up with the battery installed, the screen goes dim. Powered up with just the power cord, everything works fine, can run on AC or DC power. Just can’t have the battery installed when booting up. Is this an inverter problem, wiring problem, battery problem? How does one inverter board work with just a battery and the next one can’t have the battery installed? Weird. Any ideas are appreciated.
April 6th, 2007 at 6:57 am
by own experience friend 71 the best what you can do to get the right part is dissambly the lcd and copy al the number in the lcd becareful dont touch the cooper color in the back of the lcd, and copy all the numbers you found in the back that sound more for me like video card try hook another monitor an see if make the same if is not access http://www.impactcomputers.com get the number and speak with the rep at the ext 4 is very good and he can give some good advices.
April 5th, 2007 at 11:26 pm
Thanks for your website, it might have saved me the money for buying a new laptop.
Just to share the experience, mine is a Compaq HP NX5000. In less than a year after I bought it, the backlight was out, HP replaced it with a new display under warranty. Now 9 months later the backlight flickers or goes out altogether (if the screen is wide opened, the flicker will stop and the screen stays on). I followed your instructions and opened the display, just pressed hard on the connectors on both ends of the inverter, turned the laptop back on, it has now been working for a couple of hours since then (the trick seems to have worked, as the flicker usually came soon after the laptop is turned on). Now if the problem recur I will try cleaning or reseating the connectors first, before replacing the inverter.
Just some observations to share, if one can see faint content in the dimmed screen, most likely it is the inverter. If this situation is added with flickers which may come and go with the screen opened to an angle, it may be loose a connector at the inverter, most likely the one from the video card (opening and shutting the screen could have loosen it). If the screen stays half dim or with red colour, it may be the backlight problem (due for replacement). If there is not even faint content in the dimmed screen (screen totally black), but you can see the picture with an external monitor, then the cable from the video card may have become loose. If you cannot see anything on the external monitor, then the video card probably has a problem.
Thanks again for your website, at least now I know where the problem is and I most likely could fix it myself if it recurs.
Rgds Herman
April 5th, 2007 at 6:26 pm
I have a wierd problem where the screen looks extremely light and mouse movements look like that they have a ghosting trail. The backlight is definitely working, but..?
April 5th, 2007 at 1:21 pm
I have a Gateway 400VTX. I am following the instructions above to try to replace my inverter. I got the screen off and found (I believe) the inverter with number RT2X313. However, this number does not exist anywhere on google. Is there a way to find out if there are compatible inverters? And any idea where to get them?
Thanks.