A dead pixel test is a straightforward way to determine whether your screen has faulty pixels by presenting solid colours. It is a process that consists of changing the colors of your screen one at a time between white, red, green, blue, and black. When performing this test, it is important to check for any small dots that don't turn color. Other kinds of pixel problems may behave differently, and a dead pixel will be black on any background. This type of testing is effective because it enables each pixel's behavior to be isolated, making it simpler to recognize any defects that will not be evident during normal use. Read here for more: https://devicefixes.com/blog/what-is-a-dead-pixel/