What's the difference between a dead pixel and a stuck pixel?
Modern LCD, OLED, IPS and AMOLED panels are built from millions of tiny picture elements ("pixels"), each composed of three sub-pixels: red, green and blue. When one of those sub-pixels — or all of them — fails to behave correctly, you get a defect that's visible against certain background colours.
Dead Pixel
A dead pixel stays black on every background — the cell receives no power and emits no light. It is most visible on white, red, green or blue backgrounds. Dead pixels are usually permanent and rarely recoverable, because the underlying transistor itself has failed.
Stuck Pixel
A stuck pixel is permanently lit in one colour (red, green, blue, or any combination). It is most visible on a black background. Because the transistor still works, stuck pixels can sometimes be recovered with the rapid RGB flashing technique used in our "Fix" mode.
Hot Pixel
A hot pixel is bright white at all times — typically a defect more common on camera sensors than displays, but high-density OLED panels can occasionally show them too. Treatment is similar to stuck pixels.
Sub-pixel Fault
Sometimes only one of the three RGB cells inside a pixel fails. The pixel will look normal on most colours but tinted on others. Our solid-colour cycle (red → green → blue) reveals these by making the bad sub-pixel stand out against its missing channel.
How to use this dead pixel test correctly
For the most reliable result:
- Clean the screen first. Smudges and dust look identical to dead pixels under casual inspection. Use a soft microfibre cloth — never paper towels.
- Reduce reflections. Dim the room or angle the screen so the displayed colour is what you actually see.
- Run each colour for at least 30 seconds. Move slowly across the panel; defective pixels are often only a few millimetres wide.
- Compare colours. A pixel that is invisible on red but visible on green points to a stuck red sub-pixel.
- Use both bright and dark backgrounds. Dead pixels show on white, stuck pixels show on black.
Trying to fix a stuck pixel
The "Stuck-Pixel Fixer" mode rapidly flashes the affected area through the full RGB cycle. The constant electrical excitation can sometimes free a sub-pixel that has become trapped in a fixed state. Run the fixer over the affected region for 20–30 minutes; some stubborn pixels may need multiple sessions across several days.
Gentle physical pressure with a soft, clean cloth — applied to a powered-on screen showing the fixer animation — can also help. Never press hard: you can permanently damage the panel.
Warranty and acceptable defect counts
Manufacturers do not consider a single dead pixel grounds for return. The widely-used ISO 9241-307 standard defines four "classes" of pixel-defect tolerance, with most consumer panels shipping at Class II — typically allowing several dead/stuck pixels per million before a panel is considered defective. Premium "zero dead pixel" warranties are available from some manufacturers but usually require a separate purchase.
Always document your findings (a clear photo with the colour shown by this tool plus a coin for scale) before contacting support — most warranty teams require visual proof.
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