Defpix

Defpix is a little app designed to show you if you have any dead or defective pixels on your monitor. It works very simply: it will show you a series of solid color screens, including red, green, blue, white and black, which will allow you to tell if any of the pixels on your screen are defective. Defpix is a very simple tool and you do not have to install it, so you can quickly check your LCD monitor's health.