Notebook screen has horizontal line

Helpline Q&A Directory

An unwanted horizontal line has suddenly appeared on my laptop's display. How can I get rid of it?

Some laptop display faults (and other computer faults in general) may be caused by socketed components working themselves loose, so that one of the pins no longer makes electrical contact with its socket. This fault can be resolved by pressing every socketed chip and connector down into its socket. However, laptops are fairly intricate and it isn't a good idea to disassemble them unless you know how they are supposed to come apart (and go back together). And it certainly isn't advisable to try this if the computer is still under warranty. It's really a job for a service engineer.

Unfortunately, this suggestion might not solve your problem. In a laptop display, each pixel is individually addressable using its row and column address. Each row and column has an active device - a switch - controlling it. This switch is part of a controller chip that is part of the display panel.

It sounds like one of these switches has failed, and is therefore not turning its associated row on or off when addressed. This would result in a line, one pixel wide, across the width of the display. If this diagnosis is correct, it's a hardware fault that can only be cured by replacing the display panel. That's also a job for an engineer, and it's going to be expensive.