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:
Fixing notebook LCD screen with water damage.
Screen inverter replacement. Fixing laptop backlight problem
Laptop has bad video on the LCD screen. What is wrong?
Laptop screen shows strange colors. What could be wrong?
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February 1st, 2008 at 1:36 am
Hi,
blinking means the display is switching on and off at a faster rate. I will test it with external monitor and get back to you.
Thanks & Regards,
Ravi Shankar
January 31st, 2008 at 9:27 pm
David Stein,
Try switching the video signal from internal to external mode pressing Fn and F5 keys. Press and hold down Fn and at the same time tap a few times on F5. Maybe you can light up the external screen.
You’ll have to guess, there is no test that I’m aware of.
You can hear the welcome sound, apparently the motherboard is working. If both internal and external screens are blank even after you play with Fn+F5 keys, I would probably try replacing the video card first. This is just a guess.
By the way, try booting the laptop with an external screen when the video cable is unplugged from the video card. Find out if you can get external video when the laptop LCD is unplugged from the motherboard.
January 31st, 2008 at 9:11 pm
Ravi Shankar,
What exactly do you mean by blinking? The backlight disappears but the image stays on? Both the backlight and the image disappear?
Test the laptop with an external monitor and let me know if the same blinking appears on the external screen.
January 31st, 2008 at 9:00 pm
Aparna,
To me it sounds like a problem with the backlight lamp. Unfortunately, the only way to narrow down the problem is testing the laptop with a known good backlight lamp.
By the way, here are instructions for replacing the backlight lamp but it’s not easy. It’s only for experienced technicians. You can permanently damage the screen if something goes wrong.
January 31st, 2008 at 8:04 pm
aparna
the inverter is easier to change. may be the contacts are loose. try that first.
January 31st, 2008 at 8:51 am
I have a Toshiba m100 laptop with a discrete video card (ATI x1400).
The screen stopped working, it is totally blank with no dim image. I connected an external monitor and it is also blank. the laptop boots fine without any image, I can even login using the fingerprint reader (and hear the login welcome sound). My question is how can I tell if it’s the Mobo or the video card that is bad?
I managed to disassemble the laptop following http://www.irisvista.com/ instuctions but I dont see any physical/corrosion signs on neither the mobo nor the video card. both parts are available at SparePartsWarehouse at bout 200$ each but I dont know which one to order.
Thank you for your time and help.
January 31st, 2008 at 3:46 am
Hi,
I am facing a strange problem with my laptop. Sometimes when I am running my laptop on battery power the laptop starts blinking, then if i put my laptop in standby and again power it on the blinking disappears. The situation occurs when i switch the laptop pwer from a/c power to battery by removing the a/c power chord when working with the laptop or when i started the laptop on battery power and watch a movie in real player or windows media player and close the movie window then the display is blinking. Please help me out with a solution for the same. Eagerly waiting for your response.
Regards,
Ravi Shankar.
January 31st, 2008 at 12:29 am
I have a Toshiba M50. The screen seems to be dark but on closer inspection, one can see the desktop clearly in the background if one holds the LCD near a power source. When one closes the lid and then reopen it, the backlight gleams pinkish for a second or two, and on few occasions it seems that it is trying to turn white from pinkish. Is the problem with the backlight or the FL converter? What should be done to rectify this problem?
January 30th, 2008 at 3:29 am
cj2600
the memory works in other laptop. i will swap the cpu later on and post back. thanks for the insight.
January 27th, 2008 at 9:38 am
anoj,
Check the memory first.