A pixel that misbehaves on an otherwise clean panel is one of the more frustrating display faults. It is small enough to ignore on a busy image and impossible to ignore on a flat color. The homepage tool exists to make those defects visible by removing every distraction from the screen and cycling through pure red, green, blue, white, and black. This guide explains what the test is showing you and what your options are once you've seen it.

How a screen draws a single pixel

An LCD or OLED pixel is built from three sub-pixels — red, green, and blue — that mix to produce every color the panel can display. On an LCD, the sub-pixel itself is a tiny shutter in front of a backlight; the colors come from filters above the shutter. On an OLED, each sub-pixel is its own organic light-emitter that turns on and off without a shared backlight. The dot you see on the screen is the combined output of those three sub-pixels and the panel's electronics that drive them.

Because the colors are produced this way, a fault rarely affects "a pixel" in the abstract. It affects one or more sub-pixels. That distinction is the reason pure red, green, and blue test screens reveal so much: a sub-pixel that's stuck off won't light up on its color's frame, and a sub-pixel that's stuck on will glow against an otherwise black frame.

Dead pixel vs. stuck pixel

The terms are often used interchangeably, but they describe different physical states:

  • Dead pixel. All three sub-pixels are unresponsive. On every frame, regardless of color, that location stays black (LCD) or stays in whichever fault state the OLED defaulted to. A dead pixel is a hardware failure; software cannot fix it.
  • Stuck pixel. One or two sub-pixels are stuck in the "on" state. Against a white frame the pixel can look perfectly normal because everything is on; against a black or off-color frame it shows as a coloured dot. Stuck pixels are sometimes recoverable.
  • Hot pixel. A variant of stuck pixel that is brighter than the surrounding area on most frames. Some manufacturers do not separate the two terms.

How the solid-color test reveals them

Cycling the screen through pure red, green, blue, white, and black is the simplest reliable way to surface every kind of pixel defect on a single panel:

  1. Red, green, blue. A sub-pixel that's stuck off shows as a black dot against its color. A sub-pixel that's stuck on a different color shows up as a foreign-colored dot against the field.
  2. White. Reveals dead pixels as black dots and exposes uniformity problems such as backlight bleed, dead zones, and dirty-screen effect.
  3. Black. Reveals stuck-on sub-pixels as bright points and surfaces backlight clouding on edge-lit LCDs.

Worked example

Suppose you run the test and find one location that looks fine on white, fine on red, and fine on blue, but shows up as a green dot on the black frame. That points to a stuck-on green sub-pixel: the green emitter at that location refuses to turn off. If the same location had also shown a black dot on every other color, you'd be looking at a fully dead pixel.

What to do about it

Your options depend on the type of fault, the age of the panel, and the warranty.

Stuck pixels

Stuck pixels sometimes recover on their own as the panel warms up and cools down through normal use. There are two informal techniques that owners try when the pixel does not clear by itself:

  • Pixel-exercise videos. Long YouTube clips that rapidly cycle the three primary colors at the location of the stuck pixel. The idea is that hammering the sub-pixel through fast state changes can dislodge whatever is keeping it in one state. Reports of success exist, but there is no guarantee, and very long sessions add unnecessary wear.
  • Gentle physical pressure. Some users press a soft cloth over the pixel for a few seconds while a color cycle is running. This is risky on every panel type and especially OLED — uneven pressure can create new defects worse than the original. Most manufacturers do not recommend it.

If you do try a pixel-exercise tool, give it a bounded time window — fifteen to thirty minutes — rather than leaving it running overnight. If the pixel does not respond, longer sessions rarely help.

Dead pixels

Dead pixels do not respond to software. The decision is whether the defect is bad enough to invoke warranty service. Manufacturers publish "ISO 9241" tier policies that specify how many faulty pixels of which type are acceptable for a given panel class. A new TV with a single dead pixel near the edge often falls within tolerance; multiple dead pixels, or one in the central viewing area, generally do not.

Common mistakes

  • Confusing dust with a stuck pixel. Dust on the panel surface can mimic a dead pixel on a white frame. Wipe with a microfiber cloth (no liquid) before assuming the worst.
  • Mistaking image retention for burn-in. A faint outline of a previous static image is not a stuck pixel and is usually temporary; see the burn-in guide for context.
  • Testing at low brightness. Raise brightness to a comfortable maximum for the test — defects are easier to see when sub-pixels are working harder.
  • Pressing on OLED panels. The risk of creating a new permanent mark is real. Treat physical-pressure remedies as a last resort, if at all.

A short pre-purchase and post-purchase checklist

  • Run the solid-color cycle within the manufacturer's return window, not weeks later.
  • Document any defect with a photograph that includes the test color visible in the frame.
  • If you're under warranty, raise the issue through official support before trying remedies that could be considered tampering.
  • Save the test output — date, screen model, observed defects — in case you need it for a warranty claim.

Once you've confirmed the panel is healthy, the screen is ready for whatever you intend to put on it. If that includes long-running visuals, the next consideration is image retention — covered in the burn-in guide. If you are choosing a loop for a venue, the ambient video guide walks through what to look for. And if the picture shows defects that aren't actually pixel-level — a faint reflection, washed-out colors, an odd hue — see the calibration guide and the glare guide.

Last reviewed on 2026-04-28.