Here I’m going to post some laptop screen photos showing bad video output. I’ll explain what was wrong with the screen and how I fixed it. I plan to ad more examples as soon as I get new pictures. If you have your own example (and know how to fix it) please let me know and I’ll post it too.
Here’s some help for finding a correct part for your laptop.
Other post related to troubleshooting laptop video problems:
How to troubleshoot and fix laptop video problems
Taking apart notebook LCD screen
Replacing LCD screen inverter
The newly installed screen is not working
Example 1.
Here’s a picture of Satellite M55 LCD screen I made this morning. I got this video output as soon as I started the laptop. There were a lot of vertical lines, and they were changing color without any pattern. To me it looked like Northern Lights (never seen in real life)
. The external monitor worked fine.

As soon as I applied some tension to the screen it changed the pattern. Some horizontal lines appeared in the middle of the LCD.

Here’s the difference. When I torque the screen, the image appears but it’s distorted with some horizontal lines running across the screen.
Reseating the video cable didn’t make any change and the problem was fixed after I replaced the LCD screen.
Example 2.
I took this picture from Toshiba Satellite M65. I think that this example is very typical. One day you wake up, turn on the laptop and see one or a few hair-like vertical lines in different colors.

When you move the LCD screen some lines might disappear or more lines appear on the screen. A video output on an external screen would be perfect, without any lines. Unfortunately, these lines indicate a screen problem. I’ve never seen this kind of video output caused by a bad video cable or bad FL inverter board. My laptop was fixed after I replaced the LCD screen.
Example 3.
The photo below comes from Toshiba Satellite 5205. The laptop displays identical vertical lines all over the LCD screen as soon as I turn it on. Sometimes these lines are red, sometimes they are blue, sometimes they become wider and change color to white.

The same pattern appears on the external monitor. It displays same vertical lines. When the same video defect appears on both monitors – internal LCD screen and external screen, then most likely it happens because of a bad video card. On some laptops the video card is integrated into the system board, on other models it’s a separate module.

In this example, the vertical lines were caused by a failed video memory on the system board. I’ve tested the video memory with Microscope utility and it failed the test. In Toshiba Satellite 5205 the video memory is integrated into the system board. To fix the problem, I’ll have to replace the board. (We do not have equipment to replace the memory module itself).
Example 4.
Here’s another example of a bad LCD screen. My bad! It wasn’t the LCD screen problem.

As soon as I turned on the laptop, I was getting these reddish marks on the LCD screen but not on the external monitor. Reseating and replacing the video cable didn’t help. The problem disappeared when I installed my test LCD screen. Yes, for some reason I wasn’t able to reproduce the problem on my test LCD screen. But the reddish video appeared again as soon as I replaced the screen. I guess it happened because the system board had some kind of intermittent problem with onboard video or video connector. Long story short, I had to replace the system board and it fixed the problem. Yep, I misdiagnosed this laptop.
Example 5.
Here’s one more example of a faulty LCD screen. The left half of the screen works just fine but the right side is completely white.

Example 6.
Here’s another laptop with a bad LCD screen. This time it’s a tablet PC.

Example 7.
This screen looks like the screen on the example 1. I hooked up an external monitor and the external video works perfectly fine.

Here’s the difference. When I torque the screen, the image appears but it’s distorted with some horizontal lines running across the screen.

After a few seconds the image washes away.

I had to replace the LCD screen.
Example 8.
This laptop displays inverted colors right from the startup. As you see, the Toshiba logo is light green instead of red. The background is light gray instead of black. The Intel logo should be blue on a white background but it is red on a black background.

When your laptop displays inverted colors as on the picture above, this is an indication of a bad screen. You’ll have to replace the screen.
Example 9.
Here are two more screens. In both cases this problem is related to the LCD screen, witch means the screen has to be replaced.
On the image below you see a white band running from the top of the screen to the bottom. This band appears right from the laptop startup and runs through the logo too.

On the following image only the left side of the screen is working properly. This problem is caused by faulty LCD screen.

Are you looking for a new LCD screen for your laptop? Try here.
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December 17th, 2009 at 7:33 am
Just wanted to follow up on the great advice. I ordered a new replacement LCD cable for about $20 and installed it myself. Everything is working great now! Thanks so much for the advice!
December 16th, 2009 at 9:44 pm
Loptop working ok. but display not working ok. display low britness.
December 10th, 2009 at 9:11 pm
I had mine which had the problem but the words were not clear.i tried to format it but no respond,at point i realised was the screen was bad. i thank you for your answers.
December 2nd, 2009 at 1:03 pm
Marc,
Here’s what I do when I suspect the LCD cable failure.
1. Take apart and display panel and remove the keyboard bezel so you can access the video cable. Do not disconnect anything.
2. Turn on the laptop and wait until it boots.
3. Try moving the LCD cable while the laptop is on.
If moving the cable affects the image (it goes bad, gets garbled, LCD looses backlight, etc…), probably the cable is bad.
December 2nd, 2009 at 12:19 pm
Thanks for the quick reply. I’m glad i can rule out the inverter and backlight. Should I just replace the lcd cable, or is there an easy way to test it for shorts? On the connector to the motherboard a small piece of clear plastic looks to have been cracked and fell out when i looked under the black tape to inspect the harness connections. Could that be the source? The rest of the cable looked fine, with no visible sources of wear.
December 2nd, 2009 at 11:55 am
Marc,
I think there is a problem with the video cable, apparently there is a short inside the video harness.
A failed inverter board or backlight lamp wouldn’t garble image on the screen.
December 2nd, 2009 at 11:42 am
Wow so many problems – but none exactly like mine.
I have a Compaq Presario v2000 series. A while back the screen would become garbled if i changed the angle. Sometimes it would take a few minutes to fix itself, sometimes it could be fixed after putting it into sleep mode and resuming it would be fixed.
Just recently, i noticed that when i opened the screen the backlight seemed to turn off if the screen was open more then a few degrees.
Now, when I open it the screen works fine within the first 5-10 degrees of opening, but then it will garble and then go black.
I’ve opened it up and checked all the connections and everything is seated properly. I’ve tested it with the vga out and that works fine. So i’m not sure whether it could be the inverter or the lcd cable or the backlight. They all work fine as long as the screen isn’t open more then 5-10 degrees but after that something goes haywire.
Have any ideas?
December 1st, 2009 at 6:16 am
I have HP DV9000z laptop.
http://picasaweb.google.com/jo.....6364841538
http://picasaweb.google.com/jo.....0914568498
These lines appear within 20min after i turn on the laptop and sometimes random time. It works good with external monitor even at BIOS screen,but laptop screen has horizontal lines. Is this an inverter/lcd screen or wireless antenna related problem? I installed pc-doctor service center and checked for any hardware problems.Everything passed. When i see these lines, i tried to restart, but it keeps restarting and all i see is a black screen. I wait for 30-60 mins. and i turn it on, it works fine.
November 30th, 2009 at 2:51 pm
Messes up in Safe Mode, and locks up in Bios. GPU maybe? Thanks
November 29th, 2009 at 9:30 pm
Joe Leach,
1. What if you run your laptop in Safe Mode? Does the screen go bad in Safe Mode?
2. What if you enter the BIOS setup menu and leave the laptop in there for a while. Does the screen goes bad in BIOS menu?