How a pixel works
Each pixel on an LCD or OLED screen is made of three smaller subpixels: red, green and blue. Mixing them at different levels produces every color you see. A pixel fault happens when one or more of those subpixels stops responding to what the screen tells it to show.
The three kinds of pixel fault
| Type | What it looks like | Easiest to see on |
|---|---|---|
| Dead pixel | Always dark, whatever the image | White |
| Stuck pixel | Always lit in one color, often red, green or blue | Black |
| Hot or bright pixel | Always white or very bright | Black |
A subpixel can also be partly stuck, which shows up as a dot in a mixed color such as cyan, magenta or yellow on some backgrounds but not others.
How to check
- Clean the screen with a dry microfiber cloth. A speck of dust or a dried droplet is the most common false alarm.
- Open the dead pixel test and go fullscreen.
- Step through black, white, red, green and blue. Scan the screen in sections rather than staring at the middle.
- Note which colors the dot appears on. Dark on every color means dead. Lit on black means stuck or hot.
If the dot moves, smudges or changes when you look from a different angle, it’s on the surface, not in the panel.
Can a stuck pixel be fixed?
Sometimes. Stuck pixels occasionally recover on their own after hours or days of normal use. Dead pixels almost never do, because the subpixel or the transistor that drives it has failed.
You’ll find videos and tools that flash colors rapidly to “unstick” pixels. Results are inconsistent and there is little reliable evidence that they work. Rapid flashing can also be uncomfortable or risky for people with photosensitive epilepsy. Pressing or rubbing on the spot is a worse idea: it can damage the panel and create more faults. If a pixel bothers you, the safest route is the manufacturer or retailer.
Will the warranty cover it?
It depends on the manufacturer. Most publish a pixel policy saying how many dead or stuck pixels, of which type and in which part of the screen, qualify for a repair or replacement. Some follow the pixel fault classes in the ISO 9241-307 standard; others offer their own “zero bright dot” guarantees for a period after purchase.
Before you contact them, write down the screen position of each fault, which colors it appears on, and take a photo against a solid color. If the screen is new, the retailer’s return window is often a quicker route than a warranty claim.
When it isn’t a pixel
- A cluster or line of faulty pixels usually points to a panel or connector fault rather than individual pixels.
- A small bright patch on an LCD can be pressure damage or a backlight issue. The backlight bleed test helps separate the two.
- A faint shape that follows an old image is burn-in or image retention. Try the burn-in test.