How do I know if it is my laptop screen or the motherboard that has failed?
The short answer
Connect an external monitor or TV to the laptop: a clean picture there means the screen, its cable or the backlight has failed, while a dead external picture points at the motherboard. The external monitor bypasses the panel and the display cable, so it separates the two parts in one step. Boot the laptop with the monitor already attached before you judge the result.
What the external monitor test proves
Boot the laptop with the monitor already connected, and press the display-switch key, usually Fn with F4, F5 or F8, if the external screen stays empty. A monitor plugged in after boot is sometimes ignored, and that alone makes a working board look dead.
If the external monitor never shows the maker's logo either, the fault is on the board side. If the external monitor shows the logo and the desktop while the laptop's own panel stays black, watch that panel in a dark room while it boots. A very faint image at an angle means the panel is alive and only the backlight or its supply has failed. A panel that stays completely black points at the panel itself or the display cable.
Signs that point at the screen
Cracks, ink-like black spread, white patches, coloured vertical lines, or a picture that flickers and changes when you open and close the lid are display-side faults. A lid-angle flicker is usually the display cable rather than the panel, and the two look identical in a photo.
Touch faults and ghost input on a touchscreen laptop also sit on the display assembly rather than the board. iFixpert confirms which of the two it is at the free 21-point diagnosis.
Signs that point at the motherboard
No power at all, fans spinning with nothing on either screen, a machine that switches on and off in a loop, random shutdowns under load, dead ports or a battery the machine no longer sees are board-side symptoms. Anything after a spill belongs here too, because liquid attacks the board first.
Board repair is bench work under magnification with hot air, so iFixpert does it in Sector 49 rather than at your door. iFixpert ultrasonically cleans a spilled-on board before testing anything on it.
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Last reviewed 2026-09-06