HardwareProbe

Display Tester

Dead pixels, bleed, banding, ghosting

Before you start

Set the display to the brightness you actually use, and run at its native resolution. For the bleed test, turn the room lights off and give your eyes a minute to adjust — most reported “bleed” is just a bright room.

What to look for

A short read before each test

Dead pixel & uniformity
Look closely at each field, including the corners. Dead pixels show as black dots on the bright fields; stuck ones as coloured dots on black. Blotchy brightness on the grey field is panel non-uniformity.
Backlight bleed & glow
Turn the room lights off and set the monitor to its usual brightness. Bleed stays put when you move your head; glow changes with the viewing angle.
Gradient & banding
Step back a little and look for vertical stripes rather than a smooth fade. Some dithering noise is fine; hard bands are not.
Black & white level
You should be able to tell every patch from its neighbour. If patches 0 to 4 look identical, lower the contrast or check for a limited-range (16-235) signal.
Ghosting & motion
Track a bar with your eyes as it moves. A clean bar has sharp edges; a smeared trailing edge is ghosting, and a pale halo on the leading edge is inverse ghosting.
Sharpness & scaling
The checkerboard should read as an even grey from a distance and as crisp dots up close. Blurring, moiré or uneven line weight means you are not at native resolution, or sharpening is turned up.

This screen

Reading…