Dead Pixel
Display Defects
A pixel that remains permanently black and does not respond to any electrical signals, appearing as a black dot on all colors.
What is a Dead Pixel?
A dead pixel is a malfunctioning pixel on a display that remains permanently dark (black) regardless of what image or color is being displayed on the screen. Unlike stuck pixels, dead pixels cannot be fixed because the transistor controlling the pixel has completely failed.
Characteristics
- Always appears black on all background colors
- Cannot display any color including white, red, green, or blue
- Permanent defect that typically cannot be repaired
- Most visible on bright or white backgrounds
Causes
Dead pixels typically occur due to:
- Manufacturing defects - Flaws in the production process
- Physical damage - Impact or pressure on the screen
- Electrical failure - Complete transistor breakdown
- Age-related degradation - Natural wear over time
Detection
To detect dead pixels:
- Display a pure white screen - dead pixels appear as black dots
- Test with other solid colors to confirm the pixel never lights up
- Use a dead pixel test tool for comprehensive screening
- Examine the screen carefully in a dark room
Dead Pixel vs Stuck Pixel
| Feature | Dead Pixel | Stuck Pixel |
|---|---|---|
| Appearance | Always black | Fixed color (red/green/blue/white) |
| Cause | Complete transistor failure | Subpixel stuck in one state |
| Fixable | No | Sometimes |
| Visibility | Most visible on light backgrounds | Most visible on dark backgrounds |
Warranty and Standards
Most manufacturers follow the ISO 13406-2 standard:
- Class I: Zero defects allowed (premium displays)
- Class II: Up to 2 dead pixels allowed (consumer displays)
- Class III: Up to 5 dead pixels allowed (budget displays)
Always check your monitor's warranty policy regarding dead pixels before purchase.
Prevention
While dead pixels can't always be prevented, you can minimize risk by:
- Handling screens carefully - avoid pressure on the display
- Buying from reputable brands with strict quality control
- Testing immediately after purchase while under warranty
- Avoiding extreme temperatures during storage and use