Most monitor makers do not replace a screen for one dead pixel: their published policies accept up to 2 or 3 bright and 5 dark sub-pixels (5 in total) on standard models; Dell's non-premium monitors accept up to 5 bright, and LG's table accepts 6 bright and 6 dark on a 1920 x 1080 monitor. A bright fault (a dot that stays lit on a black screen) is treated more strictly than a dark one, and premium lines accept zero bright pixels: Dell Premium Panel Exchange (0 bright, up to 5 dark sub-pixels, for the whole warranty), ASUS and Acer zero-bright-dot models, Gigabyte AORUS for 12 months and EIZO for 6 months. Behind many policies sits ISO 9241-307:2008, whose Class II allows 2 bright and 2 dark full pixels per million pixels. Every count below was read from the maker's own page or PDF and checked on 7 October 2026; policies differ by region and change, so the warranty card for your model wins. To count faults on your own screen, use the Dead Pixel Test.
Dead, stuck, hot and sub-pixel faults
| Fault (other names) | What you see | Background that shows it |
|---|---|---|
| Dark pixel ("dead pixel"; ISO type 2) | A black dot: all three sub-pixels permanently off | White or any light colour |
| Bright pixel ("hot pixel", Dell also says "stuck pixel"; ISO type 1) | A white dot: all three sub-pixels permanently on | Black |
| Bright (lit) sub-pixel ("stuck sub-pixel"; ISO type 3a) | One red, green or blue dot that stays lit | Black |
| Dark sub-pixel (ISO type 3b) | A small dark or off-colour dot; one sub-pixel stays off | White |
| Two adjacent sub-pixels | Purple (red + blue), yellow (red + green) or cyan (green + blue) when lit | Black |
| Cluster | Several faults close together (ISO counts a 5 x 5 pixel area) | Black and white |
| Partial sub-pixel | A tiny dim dot smaller than half a sub-pixel; Dell and Acer do not count it as a defect | Needs magnification |
| Line fault | A whole row or column dim, lit or missing | Any |
Why pixels fail, and where makers disagree on the names
- One transistor per sub-pixel. Each pixel is a red, a green and a blue sub-pixel, and each sub-pixel has its own thin-film transistor. HP's white paper works the scale out for a 1920 x 1200 panel: 1920 x 1200 x 3 = 6.91 million transistors, so a single failed sub-pixel is about 0.000014 % of the panel. Damage to one of them can leave its sub-pixel permanently on or off. Apple gives the same picture for the 27-inch Retina 5K iMac: 5120 x 2880 = over 14.7 million pixels and over 44 million sub-pixels.
- Dust can look like a dead pixel. Apple says many apparent pixel anomalies are foreign material, usually irregular in shape and most visible on white. Dust on the front of the glass wipes off with a lint-free cloth; material trapped inside the screen needs a service provider.
- "Stuck" means different things. Dell calls a fully lit white pixel a "bright pixel (also called stuck pixel)" and a fully dark one a "dark pixel (also called dead pixel)". BenQ calls a white dot a "bright/hot sub-pixel", a black dot a "dark sub-pixel", and keeps "stuck sub-pixel" for a red, green or blue dot that is always on or always off. Read a policy by what it counts (bright or dark, pixel or sub-pixel), not by the word "dead" or "stuck".
- Pixel or sub-pixel? Lenovo, Acer, BenQ, LG and HP count sub-pixels; ViewSonic's tables count whole pixels (white or black); ASUS, Gigabyte and Philips count "dots", which ASUS defines as "a white or sub-pixel" that is always on (bright) or always off (dark).
- Partial sub-pixels are excluded. Dell treats a partial sub-pixel (less than half a sub-pixel) as a normal manufacturing artefact, not a defect; Acer excludes faults of 0.5 sub-pixel or less. Philips counts a red or blue dot as bright only if it is more than 50 % brighter than its neighbours, and a green dot if it is 30 % brighter.
Can software fix a stuck or dead pixel?
- Dead (dark) pixels: no. Dell: "A dead pixel has stopped working completely. No software or other methods can bring it back to life. The only solution is replacing the display panel." Acer and ISIC both state that pixel defects "cannot be fixed or repaired" and can appear at any stage of the panel's life.
- Stuck (bright) pixels: makers advise against trying. Dell tells owners not to attempt DIY fixes: pressure can crack the screen or damage internal parts, DIY attempts may void the warranty, and pixel-fixing software is "not officially supported by Dell and may not work". Dell's advice is to count the faults, compare the count with the policy and contact support.
- What we could not source. Flashing-colour "pixel fixer" programs are widely recommended for stuck sub-pixels, but none of the 13 makers checked for this page endorses them or publishes a success rate, so this page makes no claim that they work. If you try one, do it inside the return window and stop if anything changes for the worse.
- OLED is different. OLED TVs and monitors have built-in panel compensation. LG says lines or spots on an LG OLED TV can be cleared by Pixel Cleaning, which runs automatically after the TV is turned off (leave it plugged in) and can also be started from the settings menu. That is a maintenance routine for OLED panels, not a fix for an LCD transistor fault.
- Flashing screens and photosensitivity. Any test or fixer that flashes the screen should respect WCAG 2.2 success criterion 2.3.1: nothing should flash more than three times in any one-second period unless it stays below the general and red flash thresholds. The Dead Pixel Test shows steady full-screen colours for counting faults.
ISO 9241-307 pixel-fault classes
| Class | Type 1: bright pixels (per million pixels) | Type 2: dark pixels (per million pixels) | Type 3: sub-pixel total, 2 x lit + dark (per million pixels) | Clusters of type 1 or 2 (per million pixels) | Clusters of type 3 (per million pixels) |
|---|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 | 0 |
| I | 1 | 1 | 5 | 0 | 0 |
| II | 2 | 2 | 10 | 0 | 1 |
| III | 5 | 15 | 100 | 0 | 5 |
Reading the ISO classes
- Source. ISO 9241-307:2008 is a paywalled ISO standard, so the class table above is the one reproduced by the display maker ISIC A/S in its document 05867-000 Rev. G (2015), which ISIC publishes as the basis of its own warranty. The full standard was not consulted.
- Counts are per million pixels, so the allowance grows with resolution. In the same document ISIC applies Class II to real panels: 1280 x 1024 (1.31 million pixels) allows 2 bright pixels, 2 dark pixels and a sub-pixel total of 13; 1920 x 1080 (2.07 million) allows 4, 4 and 20; 1920 x 1200 (2.30 million) allows 4, 4 and 23 (table below).
- One correction. ISIC prints the XGA pixel count as 768,432; 1024 x 768 is 786,432, which is used in the table below. The fault counts are as ISIC printed them.
- Lit sub-pixels count double. The type 3 figure is 2 x (lit sub-pixels) + (dark sub-pixels), so Class II's 10 per million means, for example, 5 lit or 10 dark sub-pixels.
- Makers summarise the classes differently. Lenovo's and HP's plain-language summaries describe Class 1 as 1 bright pixel, 1 dark pixel, 2 single or adjacent bright or dark sub-pixels and up to 5 sub-pixels in total; Class 2 as 2 bright and 2 dark pixels with up to 10 sub-pixels (no more than 5 bright, in Lenovo's and HP's wording); and Class 3 as 5 bright pixels, 15 dark pixels and 50 sub-pixels. The 50 in those summaries and the 100 in ISIC's weighted total describe the same limit (50 lit sub-pixels count as 100). None of these summaries scales the counts by resolution.
- Older documents quote ISO 13406-2. Many older manuals and web pages give pixel classes from ISO 13406-2 instead. The documents used on this page (ISIC, Lenovo, HP, AOC, Philips and ViewSonic Europe) all cite ISO 9241, and AOC, ISIC, Philips and ViewSonic Europe name part 307 (2008); when a policy names a class, check which standard it means.
- Which class makers claim. AOC (US and Canada) treats as a defect anything beyond ISO 9241-307 Class 1; ISIC's monitors comply with Class II; Philips says its monitors are ISO 9241-307 compliant but publishes its own tolerance table; Lenovo says its monitors and all-in-ones "exceed ISO 9241 Class 1 and Class 2 requirements" because full-pixel faults are not permitted at all.
ISO Class II applied to common resolutions (ISIC)
| Native resolution (pixels) | Pixel count | Type 1: bright pixels (count) | Type 2: dark pixels (count) | Type 3 sub-pixel total (count) | Clusters of type 3 (count) |
|---|---|---|---|---|---|
| 800 x 480 (WVGA) | 384,000 | 0 | 0 | 3 | 0 |
| 1024 x 768 (XGA) | 786,432 | 1 | 1 | 7 | 0 |
| 1280 x 800 (WXGA) | 1,024,000 | 2 | 2 | 10 | 1 |
| 1280 x 1024 (SXGA) | 1,310,720 | 2 | 2 | 13 | 1 |
| 1600 x 1200 (UXGA) | 1,920,000 | 3 | 3 | 19 | 1 |
| 1920 x 1080 (FHD) | 2,073,600 | 4 | 4 | 20 | 2 |
| 1920 x 1200 (WUXGA) | 2,304,000 | 4 | 4 | 23 | 2 |
Brand policies at a glance
| Brand and line (standard monitors unless stated) | Bright allowed (count) | Dark allowed (count) | Total allowed (count) | What is counted |
|---|---|---|---|---|
| Acer, standard models (SXGA to UHD) | ≤ 2 | ≤ 5 | ≤ 5 | Sub-pixels |
| Acer BM series (premium) | 0 | ≤ 5 | ≤ 5 | Sub-pixels |
| ASUS, no ZBD (EU card) | 3 | 5 | Not stated | Dots |
| ASUS ZBD, 36-month (EU card) | 0 | 5 | Not stated | Dots |
| BenQ, 1920 x 1080 to 3840 x 2160 | 2 | 5 | 5 | Sub-pixels |
| BenQ, below 1920 x 1080 | 3 | 3 | 5 | Sub-pixels |
| Dell Premium Panel Exchange (U, UP, P, G, most Alienware…) | 0 | 5 | 5 | Bright pixels or sub-pixels; dark sub-pixels |
| Dell D series | 5 | 8 | 8 | Bright pixels or sub-pixels; dark sub-pixels |
| Dell E, SE and IN series | 5 | 5 | 5 | Bright pixels or sub-pixels; dark sub-pixels |
| EIZO FlexScan, ColorEdge, FORIS (first 6 months) | 0 | Not covered | — | Sub-pixels |
| Gigabyte AORUS (first 12 months) | 0 | 5 | Not stated | Dots |
| Gigabyte series | 3 | 5 | Not stated | Dots |
| HP monitors made May 2009 or later (2009 paper) | 2 (0 full pixels) | 5 | 5 | Sub-pixels |
| Lenovo monitors and all-in-ones | 2 (0 full pixels) | 5 | 5 | Sub-pixels |
| LG, 1920 x 1080 | 6 | 6 | Not stated | Sub-pixels |
| Philips (229C4Q manual) | 3 | 5 | 5 | Dots |
| ViewSonic US, below 3840 x 2160 | 2 | 2 | 3 | Pixels |
| ViewSonic Europe, up to 2560 x 1440 | 2 | 4 | 5 | Pixels |
Brand policies in detail
Each card gives the maker's own numbers and where they were read. "Bright" means always lit on a black screen; "dark" means always off on a white screen. A policy is the threshold the fault count must exceed before the maker will repair or replace the panel, unless the card says otherwise.
- Premium Panel Exchange
- 0 bright pixels or sub-pixels; up to 5 dark sub-pixels; 5 in total, for the whole warranty period (1 or 3 years, or extended)
- Covered lines
- UltraSharp U and UP, Dell Pro P (except P1424H, P1425), Dell P S series (2020 on), G and most S gaming, Alienware (except AW5520QF), C and P conferencing 24–34 in
- Other monitors
- D series 5 / 8 / 8; SE, IN, Dell Pro E and S2716DG / S2417DG 5 / 5 / 5; Alienware AW2526HL and AW2726DL 2 / 5 / 5; C large format 43 in and up 5 / 12–15 / 12–15; AW5520QF and AW3926QW 0 / 12 / 12 (bright / dark / total)
- Laptops
- HD+ (1600 x 900) and higher 0 / 5 / 5; HD (1366 x 768) and lower 2 / 5 / 5
- All-in-ones
- Premium Panel 0 / 5 / 5; standard display 5 / 5 / 5
Dell KB 000126004 Dell Display Pixel Guidelines, last modified 6 July 2026. dell.com
- Monitors and all-in-ones
- 0 full-pixel faults; up to 2 bright and 5 dark sub-pixels; 5 sub-pixels in total. The same limits are listed for every size from 13.3 in to 43.4 in
- ThinkVision P and T Series Gen-40
- Stricter: if 1 bright pixel is found during the warranty period, contact Lenovo or your service provider (added in the version of HT002800 updated 10 April 2026)
- ThinkPad
- 2 or fewer visible defective pixels is not a fault; 3 or more is replaceable within warranty (ThinkPads bought from 1 January 2008)
- IdeaPad, Lenovo and ThinkBook laptops
- Lenovo publishes the table only as an image (document HT035306); it is not reproduced here
Lenovo HT002800 (updated 10 April 2026; an archived 28 February 2025 copy has the same limits but not the ThinkVision Gen-40 note) and HT004254 (updated 3 July 2024), read from Internet Archive copies because the live pages block automated reads. HT002800 · HT004254
- Standard
- ≤ 2 bright, ≤ 5 dark, ≤ 5 total sub-pixels at every listed resolution from 1280 x 1024 to 3840 x 2160; replaced during the warranty if the count is greater
- Premium (BM series)
- 0 bright, ≤ 5 dark, ≤ 5 total sub-pixels
- Excluded
- A fault of 0.5 sub-pixel or less
Acer India, Dead Pixel Warranty Policy (support/warranty/dead-pixel), Internet Archive copy of 28 December 2025; Acer notes that duration and specification may vary by region. acer.com
- Below 1920 x 1080
- 3 bright, 3 dark, 5 total sub-pixels
- 1920 x 1080, 2560 x 1440, 3840 x 2160
- 2 bright, 5 dark, 5 total sub-pixels
- ZBD models
- Excluded from this table ("exclusive of models applicable to ZBD guarantees"); the page gives no ZBD terms
BenQ US FAQ What is BenQ's dead pixel policy?, dated 04-09-2018 on the page; "may vary from different regions". benq.com
- Bright / dark sub-pixels allowed
- 1366 x 768: 3 / 3 · 1280 x 1024, 1440 x 900, 1600 x 900: 4 / 4 · 1680 x 1050: 5 / 5 · 1600 x 1200 and 1920 x 1080: 6 / 6 · 1920 x 1200: 7 / 7 · 2560 x 1600: 12 / 12
- Higher resolutions
- Not listed (the table stops at 2560 x 1600)
LG Electronics, LG Electronics Pixel Policy (undated PDF hosted by LG Canada): "not considered a defect unless the number of bright and dark sub-pixels exceeds the maximum allowable threshold". lg.com
- ZBD, 36 months
- 0 bright dots and up to 5 dark dots for 36 months (service when there is more than 0 bright or more than 5 dark)
- ZBD, 12 months
- 0 bright / 5 dark for the first 12 months, then 3 bright / 5 dark from month 13 to 36
- No ZBD
- 3 bright / 5 dark for 36 months
- OLED monitors, no ZBD
- Service when there are more than 3 bright or 5 dark dots from 0 to 24 months
- US ZBD program
- Covers bright (always-on) sub-pixels on selected LCD products; "dark dots are not included in the ZBD program"
ASUS LCD Monitor EU warranty cards U23588 (3-year ZBD) and U23590 (OLED, 2-year), version 7, 2024; ASUS US support article 696 Zero Bright Dot (2017). Check the card that came with your model. ZBD card · article 696
- US: below 3840 x 2160
- 3 improperly operating pixels, no more than 2 bright or 2 dark
- US: 3840 x 2160 and up
- 8 improperly operating pixels, no more than 5 bright or 5 dark
- Europe: up to 2560 x 1440
- ≤ 2 bright, ≤ 4 dark, ≤ 5 combined (white / black pixels)
- Europe: 3840 x 2160 and up
- ≤ 5 bright, ≤ 5 dark, ≤ 8 combined; large-format displays ≤ 5 / 5 / 8 up to 1920 x 1080 and ≤ 8 / 10 / 16 at 3840 x 2160 and up
- VP series (Europe)
- "zero defective pixels"
ViewSonic US Limited Warranties (LCD Pixel Performance Guarantee) and ViewSonic Europe Limited Pixel Policy PDF. The US and European limits differ. US · Europe PDF
- AORUS
- 0 bright dots for 12 months; months 13–36 covered from the 4th bright dot (≤ 3 allowed); dark dots covered from the 6th (≤ 5 allowed)
- GIGABYTE series
- ≤ 3 bright and ≤ 5 dark dots allowed for 0–36 months
GIGABYTE US Monitor warranty, Internet Archive copy of 7 March 2026 (live page blocks automated reads). gigabyte.com
- Bright
- Zero bright sub-pixels, for six months from purchase (purchases on or after 1 September 2015)
- Dark
- "Dark sub-pixels are not covered by this policy"
EIZO Inc., Warranty page, Bright Pixel Policy. eizo.com
- Defect
- Any pixel fault beyond ISO 9241-307 Class 1: more than 1 full bright pixel, 1 full dark pixel, 2 single or double bright or dark sub-pixels, or 3 to 5 stuck sub-pixels (depending on the number of each)
Envision Peripherals (AOC), Warranty information, US. aoc.com
- Bright dots
- 3 single lit sub-pixels, 1 pair of adjacent lit sub-pixels, 0 white pixels; 3 bright in total
- Dark dots
- 5 or fewer single, 2 or fewer adjacent pairs, 0 fully dark pixels; 5 or fewer in total
- Spacing and total
- Faults of the same type more than 15 mm apart; 5 or fewer bright and dark in total
Philips 229C4Q user manual, section 7.1 Philips' Flat Panel Monitors Pixel Defect Policy ("This policy is valid worldwide"). Each model's manual carries its own table. documents.philips.com
- Made May 2009 or later
- 0 full-pixel faults; up to 2 bright and 5 dark sub-pixels; 5 in total; no double sub-pixel faults and none closer than 15 mm
- Made before May 2009
- 3 bright, 5 dark, 5 total sub-pixels; 0 full pixels
HP, Understanding pixel defects in LCD monitors (Bob Myers, last revised 1 July 2009), Internet Archive copy. This is the newest HP pixel policy we could retrieve; check the current warranty for your model. archived PDF
- Published number
- None. "If you are concerned about pixel anomalies on your display, take your Apple product in for closer examination"; there may be a charge for the evaluation
Apple Support 102187 About LCD display pixel anomalies for Apple products released in 2010 and later, published 9 March 2024. apple.com
Laptops, phones and the brands not listed
- Laptops. Dell treats laptops at 1600 x 900 and above like its premium monitors (0 bright, up to 5 dark sub-pixels). Lenovo replaces a ThinkPad screen from 3 visible defective pixels. Lenovo's IdeaPad, Lenovo and ThinkBook table is published only as an image.
- Phones and tablets. None of the phone makers we looked for publishes a dead-pixel count we could read. Apple's article (Macs, iPads and displays with LCD panels) gives no number and asks for an in-store examination.
- Not sourced. Samsung, MSI, Microsoft Surface and Google pages could not be read or found on 7 October 2026, so they are left out rather than filled in from secondary lists. Ask the maker for the pixel policy that applies to your model and region.
- Retailer returns are separate. A store's return window is not a pixel policy: within it, a screen can usually be returned whatever the count. Dell notes that Dell monitors bought from Best Buy in the US can be exchanged at any Best Buy store with the original receipt under Premium Panel Exchange.
How makers say to inspect a screen
| Maker | Viewing distance (cm) | Lighting (lux) | Other conditions |
|---|---|---|---|
| ASUS | 30 or more, straight on | 300 to 500 | Room temperature 20 to 40 °C |
| Dell | 35 to 50 (100 to 150 for large-format) | Not stated | Faults must be visible at normal viewing distance |
| EIZO | More than 35 | More than 500 | Typical office lighting |
| Gigabyte | 35 or more | More than 200 | Typical office lighting |
| HP (factory scan, 2009) | About 36 (14 in); about 51 (20 in) for users | 300 to 500 | Viewing angle 70–110° horizontal, 80–100° vertical |
Checking a new monitor, laptop or TV
- Use full-screen solid colours at the native resolution. Bright faults show on black, dark faults on white, and single sub-pixels on red, green and blue. The Dead Pixel Test cycles these colours full-screen; count bright and dark faults separately, because policies limit them separately.
- Look from the distance the maker uses (table above). Dell and Acer exclude partial sub-pixels that cannot be told apart from a full one without magnification, so a dot you can only see with a loupe usually does not count.
- Wipe the glass first. Apple notes that dust on the front surface often looks like a pixel anomaly; it moves or wipes off, a dead pixel does not.
- Write down the count and position (and take a photo) before contacting support, then compare with the policy for your exact line: Dell, Acer and ASUS apply different limits to premium and standard models of the same size.
- Test the rest of the hardware too. On a laptop or tablet, the Touchscreen Test finds dead touch zones and the Keyboard Tester finds keys that do not register, while the return window is still open.
Sources
- All pages and PDFs were read on 7 October 2026. Where a live page blocked automated reads, the Internet Archive copy named below was used.
- Dell Technologies, Dell Display Pixel Guidelines, KB 000126004, last modified 6 July 2026. dell.com
- Lenovo, What if defective pixel is found on your monitor - Policy and Standard, Lenovo Monitors and All-in-One desktop, HT002800, updated 28 February 2025 (archived content file); Display (LCD) replacement for defective pixels - ThinkPad, HT004254, updated 3 July 2024. support.lenovo.com
- Acer India, What is the Acer policy on defective or stuck pixel on my LCD display? / Dead Pixel Warranty Policy, Internet Archive copy of 28 December 2025. web.archive.org
- BenQ America, What is BenQ's dead pixel policy? (BenQ LCD Monitor Pixel Policy), dated 04-09-2018. benq.com
- LG Electronics, LG Electronics Pixel Policy, undated PDF (LG Canada). lg.com
- ASUS, ASUS LCD Monitor warranty card U23588 (EU, 3-year ZBD, V7) and U23590 (EU, OLED, V7), 2024; Zero Bright Dot, ASUS US support article 696, last updated 17 May 2017. asus.com
- ViewSonic Corporation, Limited Warranties (US); ViewSonic Europe Limited, Pixel Policy (PDF). viewsonic.com
- GIGABYTE, Monitor warranty (US), Internet Archive copy of 7 March 2026. web.archive.org
- EIZO Inc., Warranty: FlexScan, ColorEdge and FORIS Bright Pixel Policy. eizo.com
- Envision Peripherals Inc. (AOC), Warranty information (US and Canada). aoc.com
- MMD / Philips, 229C4Q user manual, section 7.1 Pixel Defect Policy. documents.philips.com
- Hewlett-Packard, Understanding pixel defects in LCD monitors, Bob Myers, Displays Business Unit, last revised 1 July 2009 (document c01634493), Internet Archive copy. web.archive.org
- Apple, About LCD display pixel anomalies for Apple products released in 2010 and later, support article 102187, published 9 March 2024. apple.com
- ISIC A/S, ISO 9241-307:2008 guidelines for LCD pixel defects, document 05867-000 Rev. G, 30 March 2015: reproduces the ISO 9241-307 class table (per million pixels) and applies Class II to common resolutions. isic-systems.com
- ISO, ISO 9241-307:2008 Ergonomics of human-system interaction — Part 307: Analysis and compliance test methods for electronic visual displays (paywalled, not consulted; cited through the ISIC, Lenovo, HP and AOC summaries above), published by the International Organization for Standardization, Geneva.
- LG Electronics USA, How to Fix Lines or Spots on Your LG OLED TV with Pixel Cleaning, help library, 18 August 2026. lg.com
- W3C, Web Content Accessibility Guidelines (WCAG) 2.2, success criterion 2.3.1 Three Flashes or Below Threshold. w3.org
Frequently asked questions
How many dead pixels are acceptable on a new monitor?
It depends on the brand and the product line. Standard lines at Acer, BenQ (Full HD and above) and Lenovo accept up to 2 bright and 5 dark sub-pixels, 5 in total; HP's 2009 policy was the same. LG's table allows 6 bright and 6 dark sub-pixels on a 1920 x 1080 monitor. Premium lines accept no bright pixels at all: Dell Premium Panel Exchange (0 bright, up to 5 dark sub-pixels for the whole warranty), ASUS and Acer BM zero-bright-dot models, and EIZO for the first six months.
What is the difference between a dead pixel and a stuck pixel?
Dell defines a dark or "dead" pixel as one whose three sub-pixels are permanently off, so it shows as a black dot on a white screen, and a bright or "stuck" pixel as one whose three sub-pixels are permanently on, a white dot on black. A single red, green or blue dot is a stuck sub-pixel. Makers do not use the words the same way: BenQ calls a white dot a bright or hot sub-pixel and keeps "stuck" for a red, green or blue one.
Can a dead pixel be fixed?
No. Dell says a dead pixel "has stopped working completely" and that no software or other method can bring it back; the panel has to be replaced. Acer says pixel defects "cannot be fixed or repaired". For stuck pixels Dell advises against pixel-fixing software and pressing on the screen, because pressure can crack the panel and DIY attempts may void the warranty. No maker we checked publishes a success rate for flashing-colour fixers.
What does ISO 9241-307 Class I or Class II mean?
They are pixel-fault classes counted per million pixels. As reproduced by ISIC, Class 0 allows no faults; Class I allows 1 bright pixel, 1 dark pixel and a sub-pixel total of 5; Class II allows 2 bright pixels, 2 dark pixels and a sub-pixel total of 10, where each lit sub-pixel counts twice. A 1920 x 1080 panel has about 2.07 million pixels, so ISIC applies Class II as 4 bright, 4 dark and a sub-pixel total of 20.
Will a manufacturer replace a monitor for one dead pixel?
Usually not for one dark pixel. One bright pixel is enough on zero-bright-dot lines such as Dell Premium Panel Exchange monitors, ASUS ZBD models, Acer BM, Gigabyte AORUS (first 12 months) and EIZO FlexScan, ColorEdge and FORIS (first 6 months). Lenovo replaces a ThinkPad screen from 3 visible defective pixels. Apple publishes no number and asks you to bring the product in for examination.