Check a new monitor for dead pixels before the return window closes
Every panel you buy was inspected by a machine that tolerates a few bad pixels. That sentence surprises people, but it's written into the standards — a monitor can ship with defects and still be "within spec". Which means the ten minutes after unboxing are worth more than any review you read before ordering. Once the return window shuts, a dark dot stops being the shop's problem and becomes yours.
The check needs nothing but solid colors. Busy wallpaper is camouflage; a defect that hides in a photo of a forest is impossible to miss on a flat red field.
1 – Clean the screen first. Really.
Dust does a flawless impression of a dead pixel. Microfiber cloth, one pass, before you judge anything. Support forums are littered with people who packed up a monitor, paid return shipping, and got a note back saying "speck removed". Thirty seconds. Do it.
2 – Walk the five colors
Open the guided sweep — it runs white, black, red, green, blue, then grey, fullscreen, with a caption on each telling you what a defect looks like there. If you'd rather drive manually, the white screen with the arrow keys does the same walk.
What you're reading on each field:
- A dark dot on white is the classic dead pixel — no power reaching the spot.
- A bright dot on black is a stuck subpixel, one of the three color elements jammed on.
- A dark dot on only one of red, green or blue names the exact subpixel that died. Diagnostic, if nothing else.
- Grey isn't about dots at all — it exposes patches, banding and uneven corners.
Scan slowly. Eyes track edges well and flat fields badly, so sweep in rows like reading a page. On a 27-inch 4K panel you're checking eight million pixels; give it more than a glance.
3 – Found something? Count before you box it
Manufacturers publish pixel policies, and most consumer panels are sold under ISO 9241-307 Class II — the tier that tolerates a couple of dead pixels and a few stuck subpixels per million before the warranty calls it faulty. Dell, LG, Samsung all publish their own thresholds on top; some premium lines promise zero bright pixels. Look up yours by model number before arguing with support.
The retailer's return window is a different, better lever. Inside it, "I'm not happy with this panel" usually suffices — no ISO citation needed. This is exactly why the check belongs in week one, not month three.
4 – Stuck pixels sometimes come back
Dead is dead — a dark pixel has no working circuit, and no website will resurrect it. A stuck one, glowing a single color, occasionally responds to being exercised: rapid color cycling over the area for a few minutes forces the transistor through its range. It works often enough to try, rarely enough that nobody should promise it. Ours doesn't.
Nothing on any field? Enjoy the monitor. That's the good ending.