Stuck Pixel Test
A stuck pixel is not a dead one, and the two need different sequences to find. This test starts on black — where a stuck subpixel is at its most obvious — then walks the colours that make it disappear, which is how you identify which channel is stuck.
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Recommended · 8 patterns · 5s each
Starts with the recommended setup. Nothing to configure.
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Reading the result
- 1.Find the dot on black and note where it is.
- 2.Watch that spot through red, green and blue. The colour it vanishes on is the stuck channel.
- 3.Cyan, magenta and yellow do the reverse — the stuck channel is the one they leave off, so the dot stands out most.
- 4.On white, a stuck pixel disappears. A dot that is still dark on white is dead, not stuck.
Press M during the test to mark the position — it carries into your report and makes the retest afterwards much easier.
Found a coloured dot?
Stuck subpixels sometimes release after rapid colour cycling. It is the one software approach worth trying — and it is explicitly not guaranteed.
Stuck, dead or bright?
Switch the background and watch which dots change. This is the same observation the test above walks you through, at subpixel zoom.
Stuck red subpixel
The red subpixel is stuck on
Dead / dark pixel
Every subpixel is off
Bright pixel
Every subpixel is stuck on
Each block is one pixel, split into its red, green and blue stripes. Switch the background and watch which dots change — that is the observation that tells the defect types apart on a real screen.
Why the order matters
Most screen tests start on white, because that is where a dead pixel is obvious. For a stuck pixel that is exactly backwards: a subpixel stuck in the on state is nearly invisible against a bright background and glows unmistakably against black. Starting on white means people find nothing, conclude the screen is fine, and stop.
The secondary colours are the part most tests leave out. Cyan lights green and blue but leaves red off, so a stuck red subpixel is the only red thing on the screen. Magenta does the same for green, yellow for blue. If you want to know precisely which channel is stuck — useful when describing the fault to a retailer — those three slides answer it in seconds.
Stuck pixels can come back
Unlike a dead pixel, a stuck one still receives power, which is why colour cycling occasionally frees it. It is also why a stuck pixel that disappears can return later, sometimes months later. If yours cleared after cycling, it is worth re-running this test before your return window closes rather than assuming it is fixed for good.
Worth knowing for a warranty claim: most manufacturers treat bright and stuck dots more strictly than dark ones, because they are more visible in everyday use. A single stuck pixel sometimes qualifies for a replacement where a single dead one would not — so it is worth reading the policy rather than assuming. More on what can and cannot be fixed.
What this test checks
- Stuck and bright subpixels against a black background
- Which colour channel is stuck, using cyan, magenta and yellow
- Whether the dot is stuck (vanishes on white) or dead (stays dark)
Related tests
Dead Pixel Test
White, black, RGB and gray slides — the core check.
Dead Pixel Simulator
See what dead, stuck and bright pixels look like at real size.
Stuck Pixel Color Cycling
Rapid color cycling that sometimes releases a stuck subpixel.
Screen Color Test
Extended color set including cyan, magenta and yellow.
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