Screen shows strange colors

posted in: Screen, Troubleshooting | 100

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.

TEST WITH EXTERNAL MONITOR

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…

WHAT VIDEO ON EXTERNAL MONITOR CAN TELL?

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.

TRY RESEATING LCD CABLE CONNECTOR ON MOTHERBOARD

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.

WIGGLE THE LCD CABLE

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.

APPLY SOME PRESSURE TO THE DISPLAY

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.


100 Responses

  1. @ Mignonnette Daugtherean,

    I’ve been having a problem with the colors of my monitor, there is no red, the colors that can be detected are blue, yellow and black. It happened when my laptop suddenly shutdown and when I turned it on a pink screen appeared instead of black in the startup becoming dim. some lines are visible but it will slowly fade away.

    First of all, I would test the laptop with an external monitor. If external video works properly and all colors are fine, most likely your laptop has a failed screen or video cable.
    I would probably try replacing the screen first.

    If the same problem appears on both screens, the internal LCD and external monitor, most likely this is motherboard related failure.

  2. Mignonnette Daugtherean

    dear cj, I have a sony vaio model VPCEB33FD, could you please be so kind to give me some possible reasons why I’ve been having a problem with the colors of my monitor, there is no red, the colors that can be detected are blue, yellow and black. It happened when my laptop suddenly shutdown and when I turned it on a pink screen appeared instead of black in the startup becoming dim. some lines are visible but it will slowly fade away. I’m wondering if it is due to overheating, no physical damaged was done to the screen or the laptop by the way, and I can still see what’s in the monitor but the colors are just those and it’s too dim. thanks, hoping you could help me

  3. Praneeth

    Dear CJ, This is very urgent and this is going to be a bit long but please have the patience to help me through it.
    I have 2 laptops.
    1. HP Pavilion dv6700 with failed motherboard (not using now).
    2. Sony Vaio VPCEA23EN, where a part of screen is showing some blurred line or blurred column.(which i am using)
    Can you tell me best possible solutions for this.
    I am interested to know if i can
    Relpace LED screen(Sony Vaio) with LCD screen(HP).
    My sony laptop is very slow and sometimes it hangs(mouse moves very very very slow)
    Can i put ram of hp in vaio..
    Also i am thinking of making HP 320GB hard drive into Ext HD..
    Please let me know if you did not understand anything..

  4. cj2600

    @ Ruth,
    If your laptop still works fine with an external monitor, this is not a Windows OS problem. First, I would check connection between the display cable and motherboard. Maybe it’s just a bad connection.

  5. I have an acer aspire 5551. I tried cleaning dust out of the back of my computer by loosening some screws on the back. when I saw it was a bigger job then I was willing to tackle I put screws back, but the compartment under the touch pad was then loose. the problem that developed was exactly like you picture with the external monitor looking fine. when I squished in the compartment door it would sometimes adjust and finally it stayed white until I had the fan replaced. Now it is turquoise again. the tech left nothing loose so I can’t squish the compartment door. He said it had to be a windows or theme problem. So, I am happy to find your site. I will ask him to try these solutions so I can use the laptop without an external monitor. thank you.

  6. cj2600

    @ Pam,
    You can upload the picture somewhere and give me a link in the comment. I’ll take a look and try to help if I can.
    First, when there is a problem with the image, you have to test the laptop with an external monitor. Let me know how external video works.

  7. Are you still available to help me try to figure out what is wrong with my laptop? You have a lot of good info on this site. I am hoping that I don’t have to replace the screen or laptop. I take care of my elderly in laws and I do all of their business and mine on this laptop. I do not have the money to replace it, so I am praying you can help me. It is hard for me to explain how the monitor is doing, but I do have pictures I can send you. Please let me know if you are still available to help. Thank you and God bless!

  8. @ 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.

  9. Sarah Tushemereirwe

    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.

  10. Emil Marcus

    ### 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 !

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