The screen started showing strange or wrong colors. What could be wrong? I’ve been asked this question many times and today I’m addressing the issue.

In this post I explain some basic troubleshooting techniques in case if your screen started showing strange or incorrect colors.
You have to know how to disassemble your computer in order to use following troubleshooting techniques.


The main troubleshooting step is testing the video output on an external monitor (or TV). You can connect your laptop to an external monitor using VGA cable, DVI cable, HDMI cable or S-Video cable, it depends on a type of connector you have.

Most models have a VGA connector, so it would be the most common way to connect.

Some laptops detect external monitor automatically and start showing image on both screens right from startup.
Other models can detect the monitor but display image only on one screen (internal or external). In this case you’ll have to switch video between internal and external using the Fn key and one of the F* keys in the top row of the keyboard. This combination varies for different brands, for example it’s Fn+F5 for Toshiba, Fn+F4 for HP, Fn+F8 for Dell, Fn+F7 Lenovo etc…


If both, the internal screen and external monitor (or TV) show strange or incorrect colors or any other image distortion, this is the graphics card failure.

If only the internal screen shows bad video but external image appears to be normal (as in my example), the problem is somewhere inside the laptop display. This could be bad connection, bad LCD cable or bad LCD screen.

Let’s narrow down the problem one by one.


The screen receives data signal from the motherboard via LCD cable. If the LCD cable not making good connection with the motherboard, it might cause image or color distortion on the screen. Try reseating the LCD cable connector and see if it fixes the problem. Make sure the LCD cable connector plugged correctly.

In most laptops the LCD cable connector located under the keyboard bezel (aka keyboard cover). If it’s not there, most likely you’ll find it somewhere under the keyboard.


The LCD cable runs inside the display panel, under the screen. For this test it’s necessary to disassemble the display, so you can access the cable.

A pinched or damaged wire inside the cable also can cause color distortion.

Wiggle the cable while the laptop is running. If moving the cable affects image on the screen in any way (it starts shown different colors, lines, or image clears to normal, etc…) most likely the cable is defective and has to be replaced. Try replacing the cable.

On the other hand, if moving the cable doesn’t affect image at all, most likely the cable is good and you have a failed screen. In this case you’ll have to it with a new one.


Try applying some reasonable pressure to the top part of the display assembly. Squeeze it with your fingers.

If the screen starts showing different colors, lines, or clears to normal when you squeeze the top part of the display panel, most likely this is screen failure. In this case you’ll have to replace the screen.

Also, you might be interested in the following posts:

Troubleshooting backlight failure.
How to test screen inverter.
Bad video on the screen. What is wrong?
Fix video problems.

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  1. 93
    cj2600 Says:

    @ Sarah Tushemereirwe,
    Is it an older laptop? If yes, most likely it has a CCFL LCD installed.
    When it shows no light, it’s either bad inverter or failed CCFL. I cannot tell which one failed without testing the laptop.
    First, I would probably try replacing the inverter.

  2. 92
    Sarah Tushemereirwe Says:

    Inspiron Dell laptop logs on well but displays black screen, had to read what is displayed, I have tried to increase on the light but in vain. please kindly help.

  3. 91
    Emil Marcus Says:

    ### TOSHIBA QOSMIO X505-Q720 LCD Cable ###

    Please help !

    I have a Toshiba Qosmio X505-Q720.

    Since the screen shows strange colors and lines depending on the inclination of the screen, I ran the tests your recommended, and found out that the LCD cable coming from the motherboard to the screen and inverter is pinched (wiggling it helped me come to this conclusion).

    1. Where can I find the appropriate replacement cable ? The websites you recommend do not seem to list it … actually, very few list Toshiba Qosmio, specifically the X505-Q720.
    2. How do I replace this cable ? Accessing just the screen is not enough. How do I access the place where the cable connects with the motherboard under the keyboard (What screws do I remove, etc) ?

    Thank you !

  4. 90
    Louise Ayling Says:

    I have a Sony Vaio Fz model x the graphics card was replaced 2010 & was ok until couple days ago x the
    Screen suddenly showed all the colours mixed up together like a kalaidascope x I tried it again today started in safe mode it worked so I restarted x after 10 minutes same thing happened again, colours all mixed up!
    Any ideas?
    Many thanks
    Louise x

  5. 89
    Bianca Says:

    I really need help. I have a new, one week old Asus laptop. Everything is great but the screen – it’s awful. The colors are all off. Everything seems blueish-purplish. On the one hand, many colors seem really garish on internet pages but in videos they are all dull. No calibration helps.
    It’s very unpleasant to look at it.


  6. 88
    ravi kishore Says:

    sir, i have a fujitsu siemens laptop. when i on the laptop it on’s but no image is displays on the screen.wat can i do sir pls give suggestions to me…!

  7. 87
    John Says:

    I have a problem with my Sony VAIO LCD screen. Do you think that it is the inverter problem or the LCD screen? Look at this video and see the problem I am having..­I also notice that I have connected it with external monitor and it is working normally so I guess it is not the VGA card it must be the LCD screen. Should I replace the LCD screen or the inverter?

  8. 86
    cj2600 Says:

    @ RAJ,

    My laptop is hp laptop is showing strange white lines from the time of starting the laptop.there is a fixed line at the top of the screen from the beginning.what is wrong with the laptop????

    Can you see normal Windows image on the screen at all?
    I would test the laptop with an external monitor connected to the VGA port. If external video works fine and the problem (lines) appear only on the laptop screen, this could be bad video cable or failed LCD screen.

  9. 85
    RAJ Says:

    My laptop is hp laptop is showing strange white lines from the time of starting the laptop.there is a fixed line at the top of the screen from the beginning.what is wrong with the laptop????

  10. 84
    cj2600 Says:

    @ emmanuel,

    señores laptop repair tengo un problema con un laptop dell el video se distociona la imagen cual puede ser la falla ,la pantalla o el cable lcd? gracias

    Test your laptop with an external monitor. If the video distorted on both, the laptop screen and extenal monitor, this is graphics card related failure.
    If the video problem appears ONLY on the laptop screen and the external monitor works properly, this could be one of the following:
    1. Bad connection between the video cable and motherboard or LCD screen.
    2. Failed video cable.
    3. Bad LCD screen.

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