Dead Pixel Warranty Rules: ISO 9241-307, Explained

Why "within spec" is a real sentence

A 1080p panel contains about 2.07 million pixels, and each pixel is three subpixels — one red, one green, one blue. That is over six million transistor-driven points of light, manufactured across a large sheet of glass, and producing every panel with all of them perfect would make displays dramatically more expensive. So the industry did what industries do with unavoidable imperfection: it standardized how much of it is acceptable.

ISO 9241-307:2008 establishes test methods and compliance routes for electronic visual displays. Together with ISO 9241-302, 303, and 305, it replaced the withdrawn ISO 13406-2:2001. That history matters because class labels and per-million-pixel tables from the older standard still appear in articles and product literature as if one generic table controlled every current warranty. It does not.

Three observations a policy may distinguish

Bright dot. One or more subpixels remain lit when they should be dark. A full pixel with all three channels on appears white; one lit channel can appear red, green, or blue. A black field gives any bright dot its strongest contrast.

Dark dot. One or more subpixels remain dark when they should be lit. A whole pixel dark on every field appears black; one missing channel may appear only when that primary is requested. White and the individual red, green, and blue fields separate those cases.

Channel-specific behavior. Cycling the primaries identifies which requested channel is absent or remains visible. That is an observation to report, while the manufacturer policy decides whether it counts as a bright dot, dark dot, subpixel fault, cluster, or another product-specific category.

This observational classification is what the color cycle in the dead pixel test is for. Wipe the screen first, then note the field, color, count, and location for each repeatable dot. Use the terminology in the current policy for the specific model when filing a claim.

Why online class tables are not your warranty

Class labels and per-million-pixel allowances are still widely quoted, but a table without its edition, product declaration, region, and warranty date is not enough to decide a claim. Some manufacturers publish a threshold by bright dots, dark dots, total dots, or clusters; some premium lines promise zero bright pixels; others state only a product-specific exchange rule. Do not infer “Class II” from the fact that a screen is a consumer monitor.

Resolution matters only when the current policy actually uses a per-million-pixel or resolution-banded allowance. Under such a rule, 3840 × 2160 contains 8,294,400 pixels — almost exactly four times the 2,073,600 of 1920 × 1080 — so the allowance can scale with the denominator. That arithmetic is useful after the policy supplies the rate; it cannot manufacture a rate the warranty never states.

What manufacturers layer on top

A standards framework is not the whole policy. Manufacturers write their own rules, and these differ in ways that decide real claims. Many policies distinguish bright dots from dark dots, tolerating fewer of the bright ones because a lit dot on a dark scene is far more visible than a dark dot on a bright one. Some premium product lines carry explicit zero-bright-dot promises — a guarantee that any always-on defect qualifies for exchange — while the standard tier of the same brand does not. Policies also commonly distinguish clustered faults from scattered ones, and replacement terms can differ between the initial return window and the longer panel warranty.

All of this varies by brand, by product line, and by region, and it changes over time. That is why this guide contains no brand-by-brand table: any such table starts aging the day it is written. The reliable move is to read the current pixel policy page for your specific model before you open a claim, and to bring measurements that speak that policy's language — fault type, count, and location.

Documenting a claim that holds up

First, clean the screen and re-check; dust removed is a claim you no longer need to file. Then run the dead pixel test across the full color cycle and write down what you find in the current policy's vocabulary: how many faults, whether each is bright, dark, or one channel, and roughly where each sits — “one green subpixel stuck on near center, one whole dark pixel in the lower-left quadrant” is a report a reviewer can act on.

Photograph each repeatable fault on the field that shows it clearly and take one whole-display image plus one close-up. A rigid object of known size can provide scale. Keep the model, purchase date, and serial number in private claim notes; do not place a serial number or other identifier in a publicly shared photograph, and send it only through the manufacturer's or retailer's official private support channel.

Timing matters more than most people expect. Retailer return rights inside the return window are often stronger and simpler than the panel warranty that follows — a return generally does not require you to argue fault classes at all. If you are inside that window, claim now rather than waiting to see whether the fault bothers you.

The test also offers an optional flashing stuck-pixel mode behind an explicit photosensitivity warning and confirmation. Its page labels the technique anecdotal and makes no recovery guarantee. Document the fault before trying it, do not use it if flashing content is unsafe or uncomfortable for you, and stop at any discomfort. Warranty documentation—not a browser animation—is the reliable next step for a persistent fault.

Which field supplies which evidence

The fields are not interchangeable. Each one removes a different ambiguity, which is why a claim should include the field that exposed the fault instead of only saying “dead pixel.”