Here are some tips and tricks for troubleshooting and fixing laptop video problems. Video issues are very common within portable computers and with the following tips you should be able to detect and eliminate basic laptop video problems.
Laptop LCD screen has a faint image.
Look at the LCD screen very closely and check if you can see a faint image on the screen. It’s possible that the LCD lid close switch stuck in the “closed” position and the backlight stays off even when you open the LCD screen or turn on the laptop. The switch turns off the backlight when you close the LCD display to save the laptop battery power. Check the LCD lid close switch. Usually it is a small plastic pin located close to the LCD hinges. Try to tap on the switch a few times to turn on the backlight. If after tapping on the LCD lid close switch the backlight stays on, you fixed the problem.
It is also possible that after tapping on the LCD lid close switch the backlight works fine, you see a normal video on the screen for some time and then the backlight turns itself off again. In this case I would blame the FL inverter board. Try to reseat cables on both end of the FL inverter to make a better contact between the cables and the FL inverter board. If it doesn’t help I would try to replace the FL inverter board.
Laptop LCD screen is solid white color.
Most likely it is just a bad connection between the LCD display and the system board. I would try reseating the video cable connector on the back of the LCD screen first and check if it fixes the problem. After that I would try reseating the video cable connector on the system board. I would also try reseating cables if there is no video on the LCD screen at all.
The video on the LCD screen is garbled.
Try to connect the LCD screen to an external monitor. If the external video is fine, you have a problem with the LCD screen or the LCD video cable. You can try to fix the problem by reseating the video cable on the back of the LCD and on the system board.
If you see the same garbled video output on the external monitor most likely it is not the LCD screen problem. In this case the system board (with onboard video) is bad or the video card is bad.
I understand that these tips will not cover all video problems with portable computers. If you have a different problem, you are welcome to leave a comment and I will try to help you if I can. 
Are you looking for a new LCD screen for you laptop? Try searching here.
Here’s a notebook display assembly diagram and tips for finding spare notebook parts.
Related articles:
How I took apart and repaired my notebook LCD screen with water damage
Screen inverter replacement. Fixing laptop backlight problem
Laptop has bad video on the LCD screen. What is wrong?
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April 19th, 2006 at 7:01 am
Hi cj2600
Followed your advice from post 43, changed the video cable for the laptop (12$ + shipping) and now the screen is back to its full functionnal state. A great deal compared to the 449$ flat fee for the service at ACER.
Thanks for your advice
Jean
April 19th, 2006 at 6:27 am
Having some issues with my M45 lcd. When I first boot up the computer the backlight works fine for 2 or 3 secs then goes out. I can see a faint image if I shine a light at the screen. If I unplug the fl inverter and plug it back in the backlight comes back for a couple secs and goes out. The same will happen if I switch between external video and lcd. I have replaced the fl inverter but the same thing happens. Right now I am running an external monitor.
April 18th, 2006 at 10:05 pm
Hi Jamie,
When I get a laptop with a solid white screen, I’m pretty sure that I can fix the problem by reseating the cable or by replacing the cable. If it doesn’t help (very rare) then you might have a bad LCD screen or a bad system board. The only way to find out witch one is bad is to connect a test LCD screen and see what video output you get. I guess in your case it would be better to take the laptop for diagnostics to a computer repair shop.
April 18th, 2006 at 9:36 pm
Hi. Thanks ahead of time for any help. I have a Dell Inspiron 1150 that is only displaying a white LCD screen. It displays to an external monitor just fine. I double checked and re-seated the LCD cable and then bought a new one, which didn’t do any better. I went to the Dell website to look for a new driver, but it told me that the driver I had was newer than the one I found on the site.
I can make the screen brighter or dimmer, but the only thing I ever see on the LCD screen is white – even during boot up. I can even get to the bios via the external monitor – just not with the laptop screen.
Any ideas?
April 17th, 2006 at 10:07 pm
Erica,
May be it is just a software settings. Check power options in the control panel. There is a setting to turn of monitor after some time. You can set a different time for your laptop when it runs off the battery and off the AC power.
April 17th, 2006 at 7:42 am
I have an Dell Inspiron 1200 notebook. When the laptop is running on power from the A/C adapter the backlight will only stay on for about 20 minutes. But when the computer is only running on battery power, the backlight will stay on until the battery dies. I already tried replacing the A/C adapter and that did not seem to help. Any other ideas?
April 16th, 2006 at 9:25 pm
[...] Use Toshiba Tecra 8100 display disassembly guide to remove and replace the FL inverter board. If the backlight on your computer suddenly stopped working but you still can see a faint image, then most likely the problem is caused by a failed FL inverter board. Before you jump in and start buying hardware make sure to read through laptop video problem tips. Be very careful with the LCD screen mask. The plastic is very fragile and can be easily broken. Use only your finger when you remove the LCD mask. Do not use a screwdriver or any other sharp object because you can damage the screen. [...]
April 16th, 2006 at 8:33 am
Hi Marlow,
It doesn’t look like a backlight problem. I would suspect the LCD screen itself. Try to start the laptop with an external monitor. If you get the same reddish hue on the external video, the system board (or video card) should be replaced. If the external video is fine then most likely the LCD is going bad. Usually when a reddish hue appears on the screen, the LCD screen failing itself.
April 15th, 2006 at 10:19 am
Hi George,
I work mostly with Toshiba laptops. For Toshiba laptops the output voltage on the FL inverter exit should be 200-600 VAC and the voltage before the FL inverter board should be 4.5-5.02 VDC. I have never tried to measure it myself, I just remember this numbers from Toshiba training. I think you should get the same values for HP laptop because most laptop manufacturers use the same LCD screens.
April 14th, 2006 at 7:14 pm
Would you know what the electrical value on a Pavilion HP laptop inverter should be on the lamp bulb side? It is a pk070012310 inverter in a zt1000 laptop . I would like to check it out before I order a new one . Thank you George