Dead Pixel Test
Start the test to fill the screen with a solid colour. Click or press any key to move to the next colour, and press Escape to leave.
このコンテンツは英語です。
- Press Start test. The screen fills with a solid colour.
- Click or press any key to move to the next colour.
- Look closely at the whole screen for spots that stay black, white or another colour when they should change.
- Press Escape to leave the test.
計算例
Checking a laptop screen
Starting the test and moving through the solid colours
The screen fills with one solid colour at a time, moving on with a click or key press until the test is left with Escape.
Look for spots that stay the same colour across all the screens, which can indicate a faulty pixel.
Leaving the test
Pressing the Escape key during the test
The full screen test closes and the normal page returns.
The colours cycle until you leave the test, so press Escape when you have checked each one.
Dead Pixel Test について
A dead pixel test helps you find tiny spots on a screen that do not show the right colour. A dead pixel is always black, and a stuck pixel stays one colour, such as red, green or blue, no matter what the screen should be showing. These faults can be hard to spot in normal use, because most pictures are full of mixed colours. Filling the screen with one solid colour at a time makes any faulty spot much easier to see, which is why this test cycles through several colours.
To run the test, press Start test. The screen fills with black, then moves on to white, red, green, blue and grey each time you click or press a key. Look closely at each colour and check the corners and edges as well as the middle. When you have finished, press Escape to leave the test. Where your device allows it, the test uses the full screen, and otherwise the colours still fill the window so that you can check the display.
Dead Pixel Test の使い方
- Press Start test to fill the screen with black.
- Click or press any key to move to the next colour.
- Look closely across the whole screen for spots that do not match the colour.
- Press Escape when you have finished checking.
- Clean the screen and run the test again if you spotted something unusual.
主な使いみち
- Checking a new monitor, tablet or laptop before you use it for work.
- Looking over a second-hand screen before you agree a price.
- Confirming whether a spot is dust or a fault by cleaning and testing again.
- Making sure a screen shows its colours evenly before you edit photos or video.
よくあるご質問
What is the difference between a dead pixel and a stuck pixel?
A dead pixel is always black because it has no power to light up. A stuck pixel is one that stays a single colour, such as red, green or blue, and does not change when the screen shows other colours. Both are shown more clearly when the screen fills with a solid colour, which is why the test cycles through several of them.
Can a dead pixel be fixed?
Stuck pixels sometimes respond to gentle pressure or to a special colour cycling program, but this does not always work. Dead pixels are rarely repaired, so the usual options are to check your warranty or speak to the seller. Before taking any action, clean the screen and check again, because dust or a smudge can look like a fault.
Why does the test show six colours?
Each colour reveals a different kind of fault. Black shows bright spots, white shows dark spots, and red, green and blue show pixels that are stuck on one of the main colours that make up the picture. Grey helps you spot uneven brightness across the whole screen, which can be as useful as finding a single faulty pixel.
How do I leave the test?
Press the Escape key at any time to leave the test and return to the page. If you have used the full screen mode, the Escape key also closes that mode. You can then press Start test again whenever you want to repeat the check.
Will the test work on a phone or tablet?
Yes. Tap the screen to move to the next colour, and use the Start test button to begin. Full screen support depends on the device, so on some phones the colours will fill the window rather than the whole display. The check still works well for finding faults that show up in solid colour.