Dead pixel or stuck pixel? How to tell
The two faults look similar and get confused constantly, but only one can be fixed. Telling them apart takes about thirty seconds.
Both look like a single misbehaving dot on an otherwise fine screen. They have different causes, different appearances under test, and very different odds of being fixed, which is why it is worth spending thirty seconds identifying which one you have.
The fast test
Display a full screen of pure white, then a full screen of pure black, and watch the dot.
- Black on white, invisible on black: dead pixel. No power reaching it.
- Invisible on white, glowing on black: stuck pixel. Powered but not changing state.
- Visible on both, same colour: dirt on the screen surface. Clean it.
- Dark on white, normal on some colours: partially failed pixel, one or two subpixels dead.
That last case is the one people miss, because on most content the pixel looks fine. Cycling red, green and blue separately shows exactly which subpixel failed.
Why they behave differently
Every pixel on an LCD is three subpixels, one red, one green, one blue, each with its own thin film transistor controlling how much light passes through.
A dead pixel has a failed transistor. No signal arrives, the liquid crystal stays in its default blocking state, and no light passes. It reads black on everything, so it disappears against a black background and stands out against white. Nothing can restore it, because the fault is a broken electrical component rather than a state that can be changed.
A stuck pixel has a working transistor. The liquid crystal has become physically misaligned and stopped responding to the signal, so the subpixel stays at a fixed brightness. Because it is still lit, it stands out against black. Since the liquid crystal is only misaligned rather than broken, it can sometimes be shaken loose.
What each one means for you
| Dead pixel | Stuck pixel | |
|---|---|---|
| Cause | Failed transistor | Misaligned liquid crystal |
| Shows against | White | Black |
| Can be fixed | No | Sometimes |
| Usually appears | At manufacture, or after impact | Any time, sometimes spontaneously |
| Can resolve on its own | No | Occasionally |
Stuck pixels sometimes disappear without intervention over days or weeks, which is a genuine reason to wait before starting a return on a single stuck pixel. Dead pixels never do, so there is no reason to wait on one.
Counting them properly
If you are considering a warranty claim, count in a dark room with a clean screen, going through white, black and each primary colour. Note where each defect is and which type it is, because manufacturers often set different thresholds for bright and dark defects, and some apply a stricter standard to defects in the centre of the screen than at the edges.
Photograph each one with the colour that shows it best. A photo of a black screen with a single bright dot is considerably more persuasive than a description.
Common questions
Can a stuck pixel turn into a dead pixel?
They are different failures rather than stages of one. A stuck pixel has a working transistor and misbehaving liquid crystal. A dead pixel has a failed transistor. A stuck pixel can become permanent, but it does not become a dead pixel.
What is a hot pixel?
A hot pixel is a stuck pixel showing white, meaning all three subpixels are stuck on. It is the most visible variety and shows up most clearly against black. Some manufacturers count hot pixels more strictly than coloured stuck pixels in their warranty policies.
Why does my pixel look black on white but fine on colours?
That is a partially failed pixel, where one or two of the three subpixels have died. It appears dark on white because the full brightness is missing, but still responds on the colours whose subpixels still work. Cycling red, green and blue shows which subpixel failed.
Does the distinction matter for a warranty claim?
Sometimes. Some manufacturers set different thresholds for bright (stuck) and dark (dead) pixels, and bright pixels are often treated more strictly because they are more noticeable. Knowing which you have helps you read the policy correctly.