How to check a screen for dead pixels: Step-by-step guide for TVs, monitors, and smartphones

A dead pixel is a tiny spot on a display panel that can ruin the whole picture once you notice it. In 2025, with OLED and mini-LED screens becoming standard, even a single defect on a 4K display can be irritating. Checking for dead pixels before buying—especially on used devices—is essential, as many manufacturers don’t consider one or two faulty pixels a defect. Here’s how to quickly identify the issue on a TV, monitor, or smartphone without special tools.

What Dead Pixels Are and Where They Come From

A pixel is the smallest image unit made up of red, green, and blue subpixels. When one fails, it can behave differently:

• Dead pixel – always black.
• Hot pixel – always white (usually due to a controller malfunction).
• Stuck pixel – permanently shows one color (for example, red).

Common causes include manufacturing defects, impacts, overheating (above 60°C), wear and tear (especially in OLEDs), or exposure to extreme cold. Dead pixels shouldn’t be confused with burn-in, which is a gradual fading of brightness when pixels display static images for long periods (like TV logos or game HUDs). In 2025, mini-LED and QD-OLED screens are more resistant to burn-in, but testing is still recommended.

Can they be fixed? Occasionally. Gentle rubbing with a cotton swab can sometimes help with stuck pixels, as can software like PixelHealer, which rapidly cycles colors. However, success is not guaranteed.

Universal Method: Solid Color Screens

This method works for any display — TV, monitor, or laptop.

1. Set brightness and contrast to maximum.
2. Display solid colors one by one: red, green, blue, white, black, and gray.
3. Inspect the screen from a distance of 30–50 cm (12–20 inches) and at an angle — defects are easier to spot that way.

Where to get test images:

• Online:com, checkpixels.com
• Offline: Download image packs (“pixel test images 4K”) or create your own in Paint using color fills.

Checking a Monitor or Laptop

1. Connect the display to your computer.
2. Run Dead Pixel Tester (Windows) or open an online test in your browser.
3. Switch between colors (use F11 for fullscreen).
4. Disable auto-brightness on laptops for consistent results.

In 2025, EIZO Monitor Test and UFO Test (for refresh rate) remain must-have tools for gamers.

Checking a TV

1. Download test videos or images to a USB drive (search “TV pixel test 4K HDR” on YouTube and download via yt-dlp).
2. Plug the USB drive into your TV and open the media player.
3. Play color screens one by one — red, green, blue, black — for 5–10 seconds each.
4. Inspect from both a typical viewing distance and up close.

2025 tip: Search YouTube for “dead pixel test 8K” — most modern Smart TVs support 60 fps playback for smoother transitions.

Checking a Smartphone: Engineer Menu and Apps

Via apps (simpler):

• Install Dead Pixel Test (Android/iOS).
• Launch it, choose a color, and switch to fullscreen.
• Swipe your finger across the screen to check for unresponsive or discolored pixels.

Via engineer menu (more precise):

• Samsung: Dial *#0*# → choose RED, GREEN, BLUE, BLACK.
• Xiaomi / Redmi / POCO: Settings → About phone → tap Kernel version 7 times → find RGB tests.
• Huawei / Honor: Dial *#*#6130#*#* → choose color screens.
• Google Pixel: Settings → About phone → tap Build number 7 times → open Developer options → enable Show taps for visual tracking.

Bonus: Run the TOUCH test — swipe across the grid; gaps indicate dead touch zones.

In Brief…

Dead pixels are black, white, or colored dots that never change color. Always test displays before purchase using solid color screens (red, green, blue, black) at full brightness.

• Monitors/laptops: Use online testers or Dead Pixel Tester.
• TVs: Load 4K/8K test videos via USB.
• Smartphones: Use *#0*# (Samsung), kernel taps (Xiaomi), or a dedicated app.

One dead pixel usually isn’t covered by warranty, but two or more often are grounds for return.
By 2025, a pixel test takes just two minutes—and can save years of frustration.