How It Works
- Clean the screen first so dust isn't mistaken for a defect.
- Go fullscreen and let your eyes adjust.
- Start on white — dead pixels appear as black dots.
- Switch to black — stuck/bright pixels appear as coloured or white dots.
- Cycle red, green, blue to catch stuck sub-pixels.
- Photograph any defect against the colour where it's most visible for a warranty claim.
Frequently Asked Questions
What is the difference between a dead pixel and a stuck pixel?
A dead pixel gets no power and stays black on every colour. A stuck pixel still lights up but is frozen on one colour (usually red, green or blue).
How does a dead pixel test work?
It fills the screen with one pure colour at a time so any pixel that doesn't match the background stands out.
Can dead or stuck pixels be fixed?
True dead pixels usually can't be fixed. Stuck pixels sometimes respond to rapid colour-cycling ("pixel exerciser") software run over the spot for 15-60 minutes.
How many dead pixels are normal?
Under ISO 9241-307 (the standard that replaced ISO 13406-2), most consumer panels fall in Class II, which permits up to 2 bright, 2 dark, and 5-10 sub-pixel defects before warranty replacement. Policies vary by brand — Dell's Premium Panel Guarantee, for example, promises "zero tolerance for bright pixels" and replaces an UltraSharp display on a single bright pixel, while standard monitors follow the ISO Class II thresholds.