Fixing bad video on LCD screen

posted in: Screen, Troubleshooting | 886

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.

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.

LCD screen no image

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

LCD screen horizontal lines

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.

Laptop LCD vertical lines

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.

Laptop screen vertical lines

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.

External screen vertical lines

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.
Bad reddish laptop screen

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.

Half LCD screen not working

Example 6.

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

Vertical stripe on LCD

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.

vertical lines

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

distorted image

After a few seconds the image washes away.

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.

Inverted colors

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.

White band running from top to bottom

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

Only left side of the screen works

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

886 Responses

  1. Do you think that I need to replace my LED screen?

    (Notebook screen doesnt dispaly Red color
    A Notebook screen doesn’t display red color on objects, but entire screen covered with light pink vertical lines expect small area on top of screen. In this small area, can see all colors as normal. Vertical lines are not constant. When I connect an external monitor via VGA port it is fine and working without any issue. I dismantle the notebook and check cables and LED screen for loose connection but it didn’t help. It is a Samsung NP300E series notebook. What can be the cause for this problem?)

  2. Hello I dropped my mobile and though it hit the screen of my new Hewlett Packard laptop there appears to be no crack. But the screen is half white with vertical lines and the bottom half is black. I’m unsure what to do. The screen image looks cracked in the bottom right hand corner where the mobile phone landed but its smooth to the touch. Can anyone advise?

  3. Hi, I have the exact same pattern as your example number 1. I have been trying to upgrade my Dell XPS M1330 from the chunky CCFL backlit LCD to the slim LED backlit version. I purchased all the required parts, but the replacement LED screen appears to be faulty. I’ve tried two separate new screen cables with no success. At the moment I’m back to the original chunky CCFL which is o.k. just not very modern.
    Good article.

  4. varsha

    hi there!!

    i have exactly the same problem as in example 5 above but it s much thinner band about 1 cm on the right side. it keeps increasing in width gradually!! can it be repaired safely without screen replacement and what is the reason it happens.

    Can i stop it from increasing in width, coz i wouldn’t mind a 1 cm band on right much :P

    thank you!!

  5. cj2600

    @ Ameet,

    My TOSHIBA laptop monitor briefly comes on and then goes blank after 2/3 seconds. The display after connecting the laptop to an external monitor via VGA cable works fine.

    Pls. advise, what could be the source of error – is this an issue with the hardware or some monitor drivers ?

    This is definitely hardware related problem.
    Take a closer look at the laptop screen after it fails. Is it really blank? Can you see a very dim image on the screen?
    If you can see a dim image, most likely it’s either failed inverter board or failed backlight lamp inside the screen.
    I would try replacing the inverter board first.

  6. cj2600

    @ vivek,

    i’ve dell studio 1555…for last two days suddenly some color lines come on scree and thn screen becomes blank…after restartting sometimes it run for hours without any problem and sometimes those lines come again and screen goes blank..

    First thing to try – test your laptop with an external monitor. Can you recreate the same problem on the external monitor?
    If external video works fine and the problem appears only on the laptop screen, this could be related to one of the following:
    - Failing LCD screen.
    - Failing video cable.
    - Bad connection between the video cable and motherboard or LCD screen.
    If that’s the case, try reconnecting the cable first. After that replace the LCD screen and video cable.

    If the same problem appears on BOTH screens and external video goes bad the same way, this problem is related to the motherboard failure.

    Just in case, try removing memory modules one by one and test the laptop with each memory separately. It’s not likely but could be memory failure.

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