How to check a new monitor for dead pixels and the right refresh rate
Check a new screen while you can still return it. Two tests cover most of what can be wrong out of the box: solid colors for bad pixels, and a refresh rate check to confirm the screen runs as fast as it should. Both run in the browser and take about ten minutes together.
1. Look for bad pixels
- Wipe the screen with a dry soft cloth. Dust looks exactly like a dark pixel.
- In the system’s display settings, use the resolution marked as recommended for the screen.
- Open the dead pixel test and press Start full screen.
- Go through the five colors: black, white, red, green, blue. Click or press the right arrow to move on. Nothing changes by itself.
- On each color, scan the screen in rows from a normal viewing distance, then lean in for anything suspicious.
| On this color | Look for |
|---|---|
| Black | A dot that stays lit, in white or a single color. In a dark room, also brighter patches near the edges. |
| White | A dot that stays dark or tinted. Also areas that look dimmer or yellowish. |
| Red, green, blue | A dot that stays dark on one of the three, or one that shows a different color. |
A real fault stays in the same place every time you come back to that color, and it does not move when you wipe the screen. If you find one, take a photo with something for scale and note where it is. Whether it qualifies for an exchange depends on the maker’s policy for that model, so check the warranty page before you contact the seller.
2. Confirm the refresh rate
Open the refresh rate test on the new screen and wait two seconds. It times 120 frames and shows what the browser is really drawing. A frame every 16.67 ms is 60 Hz. A frame every 6.94 ms is 144 Hz.
If a 144 Hz monitor shows 60, check the settings before you blame the screen. Look at the refresh rate in the system’s display settings, then press Measure again. If the window sits across two monitors, move it fully onto the new one first.
3. Write down what you saw
- Date, and how you tested (full-screen colors, recommended resolution).
- Where any dot is, and on which colors it showed.
- The refresh rate you measured and the setting you chose.
With these notes you only have to test once, and you can describe the problem exactly if you need to contact the seller.