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My computer: Dell Latitude D620

I have these lines going horizontally across my entire screen making it completely illegible. So naturally I replaced the monitor. However similar pattern of distortion appeared here too.

So I figured the graphics card may be faulty so I tested the external VGA port. But that displayed perfectly fine!

I even tried connecting the the LCDs to another laptop (which had the same input), and I was able to see the display was working (even though the backlight wasn't but that's probably because it wasn't the correct model for that laptop).

So if anyone could suggest anything that may point to what's at fault or how to go about fixing this I'd be most appreciated.

Thank you.

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What system is run on your computer? Do you have the latest graphics drivers? – w4etwetewtwet Jun 2 '13 at 8:19

Turn the system off, and hold the d key while pressing the power button.

This will initialize a LCD Built in Self Test (BIST).

You will hear some beeping, and see flashing color screens. Take note of any lines that may appear. If you see lines in the colored screens, it would indicate there is a problem with your LCD panel itself. If you do not see the horizontal lines in the BIST, but do see them in the system BIOS... it may indeed be a bad video card

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Thanks for your advise. Holding d didn't do bring up the test but fn key did. On the full colored screens there were no lines, but all the other screens (instructions, bios etc...) did have. I'm also wondering, is it possible that somethings wrong with the video card, but external monitors still display correctly? Thank you. – scrollup Apr 21 '13 at 16:27
No lines on the test, but lines in the BIOS menu indicate a faulty video card in most cases. Since it's most likely integrated graphics, I don't know what to suggest besides an external monitor if that works. Sorry, and good luck! – David Houde Apr 23 '13 at 2:42
Thanks for your reply. But since the external monitor does work and display correctly, wouldn't that indicate that the video card is fine? If so where else could the problem be? It seems to be something that's between the video card and LCD. – scrollup Apr 23 '13 at 14:53
Just because the external monitor works fine, does not mean that the Graphics Card is not faulty. Graphics cards have 'heads' for each display output they support. Its possible one head can be faulty, and the other work fine. – leinad13 Jan 19 '14 at 13:28

maybe its in the flex-cable that connects the monitor ton the board, try moving the monitor slightly open and close and see what happens, I have a portable DVD player that has that problem and if I slightly close the monitor a few degrees down they go away! It's not worth fixing so I tossed it. If it's a cord with a multi wire type it may be fixable by finding the bad wire If its a flat ribbon type you'll have to get a new one.

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