Find and Name the Fault
Run the dead pixel test full screen and look across each solid color from about 30 cm (1 foot) away. Note which colors show the dot and roughly where it is.
- Black dot on white: a dark pixel, often called a dead pixel. All three of its subpixels stay off.
- White dot on black: a bright pixel. All three subpixels stay on. Dell calls this a stuck pixel.
- Red, green, or blue dot on black: a bright subpixel, where one subpixel stays on.
- Small dark spot on white: a dark subpixel, where one subpixel stays off.
Names vary between makers, so describe what you see, and on which colors, when you contact support.
Rule Out Dust First
Apple says many pixel anomalies are foreign material on the front of the glass or trapped inside the display. Material like this is usually irregular in shape and easiest to see on white.
- Turn the screen off and wipe it with a lint-free cloth.
- Run the dead pixel test again on the white screen.
- If the spot moved, changed shape, or disappeared, it was dust, not a pixel fault.
Material trapped inside the display can't be wiped away. It needs a service center.
Why a Pixel Stays On or Off
Each pixel on an LCD has red, green, and blue subpixels, and each subpixel has its own transistor that turns it on and off. When a transistor fails, its subpixel stays off (dark) or on (bright).
Dell says a dead pixel has stopped working completely, and no software or other method can bring it back.
Pressure and Pixel-Fixing Software
Dell's advice is not to fix stuck pixels yourself. It gives these reasons:
- It can damage the display further.
- Pressing on the screen can crack it or damage parts inside.
- Pixel-fixing software isn't supported by Dell and may not work.
- It may void your warranty.
Pixel-fixing videos and tools flash colors rapidly. The web accessibility guidelines (WCAG) limit flashing to three times in any one second. Faster flashing can trigger seizures in people with photosensitive seizure disorders, and people are even more sensitive to red flashing.
For that reason, Hardware Test doesn't offer a pixel flasher. Its screen tests change colors at most three times a second.
Count the Pixels and Check the Policy
Each maker publishes a pixel policy that says how many faulty pixels qualify a screen for replacement. A few faulty pixels can be within policy. Dell, for example:
- Monitors with Premium Panel Exchange (UltraSharp, Alienware, gaming, and professional models): zero bright pixels allowed for the whole warranty.
- Standard monitors: up to 5 bright pixels or subpixels allowed before a replacement.
- Laptops with HD+ screens: zero bright pixels and up to 5 dark subpixels.
Find your maker's policy on its support site, and check the seller's return window too. A return can be simpler than a warranty claim for a new screen.
Get It Repaired or Replaced
- Dell: if the count qualifies, contact Dell Technical Support for a replacement.
- Apple: take the device to an Apple Store, an Apple Authorized Service Provider, or an Independent Repair Provider. There may be a charge for the evaluation.
- Other makers: contact support with the count, the colors that show each dot, and where on the screen it is.
When the new or repaired screen arrives, run the dead pixel test again, and the monitor test for uniformity, banding, and sharpness.