Lines or flickering on my screen

First of all, look at the nature of the fault : fixed lines that never move, lines that come and go, or a whole image that flickers. Those three behaviours point to different causes.

The test that rules out half the causes

On a laptop: plug in an external monitor. If the picture is perfect there, the graphics side is fine and the problem is in the screen or its ribbon cable. If the lines appear on the external monitor too, the graphics card is at fault.

On a desktop: change the cable, then the monitor. It sounds obvious, but an HDMI or DisplayPort cable that is loose or damaged produces exactly these symptoms.

The startup test

Are the lines there from the manufacturer's screen, before Windows loads ? If so, the problem is hardware - no driver is loaded at that point. If they only appear once Windows has started, the graphics driver becomes a serious lead.

What each symptom suggests

• Fixed vertical lines, always in the same place: a failing panel or a partly disconnected ribbon. On a laptop, test by moving the screen angle very slightly : if the lines change, it is the ribbon or its connection.
• A flickering or blinking image: often the refresh rate set wrongly, or a cable of poor quality for the resolution being asked of it. Check that setting in the display options before anything else.
• Washed-out colours or a strange cast: a loose cable, or a bent pin on older connectors.
• Squares, scattered pixels, distorted textures: the classic symptom of a graphics card in trouble, often tied to overheating.
• A dark patch or halo that spreads: a physically damaged panel - see broken screen.

What you can try

• Cleanly reinstall the graphics driver from the card maker's or the machine maker's site.
• Check the refresh rate and the resolution in the display settings.
• On a desktop, push the cable firmly home at both ends, and if the machine has a dedicated graphics card, make sure the monitor is plugged into it - not into the motherboard output.
• Start in safe mode : if the display is perfect there, the cause is software.

What calls for a repair

A video ribbon can be replaced, and so can a panel. A dedicated graphics card is swapped easily on a desktop ; on a laptop where it is soldered, the repair becomes considerably heavier and replacing the machine comes into question. See repair or replace.

A diagnosis tells you which side you are on before you spend anything. We do it free of charge, in Lyon and across the Rhone.

Frequently asked questions

Would you rather we took care of it ? See our laptop screen replacement service, in Lyon and across the Rhone.