How to use it
- Wipe the screen: dust looks a lot like a dead pixel.
- Turn brightness to the maximum.
- Press Start screen test. Click or press → for the next color, ← to go back, Esc to stop.
- Look at each color from where you'd normally sit, then up close, edge to edge.
What each color shows
- White: dead pixels (black dots) and a yellow or blue tint.
- Black: stuck pixels that stay lit, and light leaking from the edges (backlight bleed). Best in a dark room.
- Grey 50%: burn-in. On OLED screens, look for a faint ghost of the taskbar, icons or windows.
- Grey 25%: blotches and uneven, cloudy areas.
- Red, green, blue: pixels showing the wrong color.
- Gradient: visible steps instead of a smooth fade (banding).
Questions
What's the difference between a dead and a stuck pixel?
A dead pixel never lights up, so it shows as a black dot on white. A stuck pixel is stuck on one color, so it shows on black and on the other colors. Stuck pixels sometimes come back after a while; dead pixels don't.
How many dead pixels are acceptable on a used laptop?
One near the edge is a reason to ask for a lower price. Several, a cluster, a line, or anything in the middle of the screen is a reason to walk away: replacing a laptop screen often costs a large part of a used laptop's price.
Is burn-in fixable?
No. OLED burn-in is permanent wear. If you can see the taskbar ghost on the grey screen, it will only get worse.