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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January 3rd, 2007 at 5:18 pm
hello, i own a compaq evo n800c laptop and i recently replaced the bezel around the keyboard which required the screen be removed. upon rebooting after the install the colors are all distorted with a lot of neon colors (blue pink green) making any picture or video impossible to see. i tried reseatting the cables off of the lcd onto the laptop itself and the problem remained. any ideas?
January 3rd, 2007 at 11:12 am
Dear Laptop Repair Guy,
Thanks so much for the posts. I have a question about the 5205 model you posted with the video artifacts. I have the same identical problem with my laptop, 5205-S703, but it does not appear from the moment I turn my laptop on. Sometimes it does when I turn the laptop on after immediate prior use, but not the first time in the day. It happens on both the main LCD and any external monitors when it does happen, though. I think that this might be a problem with my system fan, because when I use high power apps, the glitches reappear and the computer freezes. The system can run for about 20 minutes if I dont use it intensively before the artifacts appear. Also, when I hold the laptop and apply pressure to the underside of the laptop near the fan and VGA area, the lines dissappear (but the system remains frozen if already frozen). Have I diagnosed my problem correctly as a fan malfunction, or do you think the video card is fried. The reason I suspect it is a fan problem is because my laptop once had intermittent fan grinding problems, and I think it may have finally died. One final thing, I thought the VGA board on 5205 laptops was discrete? Am I wrong? Thanks for your time and help.
With much appreciation,
Joseph Issa
January 2nd, 2007 at 10:37 am
i purchased this laptop on 5/28/04 from Gateway 450 ROG online. It started giving me problems about a year ago. The screen kept flickering and then a lil while ago it just went red and constant flickering. I was advised that it was just the video cord that needs to be replaced. i actually bought this item from ebay if this correct i wanted to know if that could be the problem thanks
December 31st, 2006 at 12:03 pm
Syed,
I don’t work with motherboards on component level, but I think it’s not possible. Probably you’ll have to find a technician who can resolder the connector on the motherboard and see if it can help to fix the problem.
December 31st, 2006 at 10:44 am
Mika,
Hard to say what is wrong, the video cable or the LCD screen. Unfortunately there is no way to find it out until you replace at least the video cable. Before you replace anything try reseating the cable on the LCD site. HP manuals do not provide any instructions on replacing the video cable, you’ll have to figure it out yourself. Take a look at Toshiba laptop disassembly guides. Some of them show how to open the display, it will not be much different for HP laptops. From my experience with HP laptop I found that the LCD mask is glued to the screen. To separate the mask from the screen I use a guitar pick (you can use any other piece of soft plastic). I insert the guitar pick between the LCD mask and the screen and carefully move it alone the edge until the mask separates from the screen.
It’s hard to find just the video cable for HP laptops. I think HP does not sell video cables separately from the display assembly. Check out this website, they have full list of parts for HP/Compaq laptops. I would contact the seller, may be they can help you to find just the video cable, it might be included in one of miscellaneous kits they sell.
December 27th, 2006 at 2:53 pm
My dad basically just ran a magnet (from a portable FM device) in front of his LCD on his laptop (accident). Now the screen is in bars of blue, green and some white, predominately on the left side of the screen and across the top. He says it appears “smeared.”
Is this something there is a way to reverse? He says he is pretty sure it is magnetic damage to the LCD; the computer itself appears to be working fine. He can’t search the ‘net himself as he can’t navigate with the damage to the screen and asked me to see what I could come up with. So far, this seems to be the best place to look for answers!
Thank you,
Cindy in AK.
December 26th, 2006 at 11:41 am
thanks for the reply. well i removed the strip today. took the white 30 pin connector coming from the lcd into the motherboard, out. checked the pins inside the white female connector onboard, which was OK. the 30 wire cable is well in placed in its male connector.placed the connector securely back into its female.when i press the white connector on board the display chnages. seems like there is always a blue overlay on this screen formed by very thin vertical lines, which has taken away the crispness of the image on the lcd.the connector is very sensitive, even if i press is lightly the display changes.the cable is ok from the end where it goes into the lcd. Does this description ticks any thing??? i cannot solder it again on the board as it is very tiny connector with 30 pins. what ticks me is a bad connection b/t the motherboard and the female conector on the board. is there anyway that i can convert the 30 wire cable from the lcd into the external monitor port, so instead of video signal from the on board connector i can use video signal from the video port at the back. i was good at electronics in the university:)
December 26th, 2006 at 12:36 am
Hello!
I have Compaq evo n800w UXGA laptop. When I start it, display becomes first greenish and after that picture is harsh and blurred but colors are OK. I had to drop down resolution to xga level that I can read any text seen on display. I have changed drivers with no help. On external display picture is OK. I have unplugged Lcd cable and put it back with help of manual but no help. Is it possible that some cord of ldc cable is broken or other edn of it is loose? Is it possible to change that cable on that particularly model? Is there any instructions available? No warranty anymore. HP offers only replacing whole display and the price is over 1000€ !!. Can anyone help with this problem? Yours Mika
December 25th, 2006 at 8:18 pm
Syed,
If the laptop is still under warranty, send it to Toshiba.
Here’s what you can try to narrow down the problem:
Remove the keyboard securing strip as it shown on the steps 6,7,8 of this disassembly guide in order to get access to the video cable and connector on the system board. Try reseating the video cable and test the laptop after that. It might be just a loose video cable. Be very careful when you unplug and plug the cable to the system board, there are two rows of fragile pins inside the connector.
I think your problem could be related to a) loose connection, b) bad video cable, c) defective video connector on the motherboard. I don’t think the motherboard itself is bad because the external video works fine.
December 25th, 2006 at 8:05 pm
Harry,
If the laptop LCD screen and external monitor display the same bad video (horizontal lines), most likely you have a bad motherboard, I assume the video card is integrated into the motherboard.