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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August 14th, 2008 at 12:25 pm
First, thanks for all the information here on this site. Second, perhaps you might have help for my particular problem. I have a HP Touchsmart IQ770. It’s not a laptop of course but it is an all-in-one. It’s just over a year old but only has been used for three months. Here’s what’s happening. It’ll turn on and boot up great sometimes. But sometimes after using the screen turns to a mash of flickering moving lines of color that continuously form vertical and horizontal lines that move up and down and across the screen. This problem is cured only by unplugging the computer and letting it sit for two-three days. It has to be unplugged. If plugged in again before two days it’ll look similar to the first screen on this page or you can hear it boot up but the screen is nothing but moving colors. Any advice would be great. Best Buy wants to replace the mother board.
August 14th, 2008 at 9:13 am
I have the same problem as number 4. However it also goes into a black screen sometimes. However when I press down on the left hand side of the laptop near where the gateway logo is its comes back to normal. I have a gateway m320x. When I connect it to an external screen I ahve no problem and the display is just fine. Any advice on what might be the problem and if its a board how much it would cost.
August 14th, 2008 at 2:35 am
my laptop Accer,is turning on but no display.how shold l fix it.lm a computer technician ,l need to lean how to repaire laptops
August 11th, 2008 at 11:00 pm
ilian portillo,
That description sounds like you have a bad LCD screen.
August 11th, 2008 at 2:41 pm
hey whats up man! i have to say that mines is doing what example 5 is doing! but it changes from time to time, sometimes i get it just in the middle and it changes to various color only when i push where the line is at! so i guess ima have to get and lcd screen! i check with a external screen and it works fine so im thinking its nothing else but the lcd screen! if you think its something else feel free to email me! or if you have any other suggestiong before i purchase a new screen some tests i might be able to run!
August 6th, 2008 at 5:41 pm
I recently bought a new TOSHIBA M305-S4819 with Windows Vista. After a while, the screen starts blinking on and off, with horizontal lines, and then turns completely black. The system continues working well.
Taking advantage of the manufacturer’s warranty, I took it to a technician who changed the LCD screen. At the beginning looked OK, but the problem persisted. Then, I took it to a different technician who changed the board and memory, but the problem continued. Finally, I took it to Toshiba Technical Center. They checked everything on the BIOS, but the problem continues. They said that Graphic Settings was reset, but I am not satisfied with that. Please send me any idea what is going on Thanks.
August 6th, 2008 at 9:35 am
Yea I have this laptop and the screen keeps blinking on and off but when its off its not completly black but its enough to cause panic. I have a Gateway…the Vista type. If you can help please email me back at mobleyo@merrimack.edu Thanks!!
August 1st, 2008 at 8:49 pm
I recently bought a used HP and it has a TINY red line on the left im wondering if there is a fix for this or how much it will cost for a new screen plz reply to this by sending me an email
July 30th, 2008 at 11:08 pm
Oh ok thanks
was hoping it was just the cable. i checked yesterday that it was seated properly and it was and also i plugged it into an external monitor and it was fine on that. Its a Dell inspiron 6000. Are the screens expensive on these do ya know?
Many thanks for the excellent advice and super fast response!
July 30th, 2008 at 12:21 pm
DaveUK,
I would say it’s bad screen.