Do flat screen monitors wear out?

Yesterday I got a shock. I switched on at the mains and my monitor was dead. Normally I get a brief Dell logo and then a built-in screensaver. After a bit of switching on and off, it did come on and was perfectly OK for the rest of the day. Today I can't get it to work at all. I'm annoyed because that was my best monitor. The one I'm using now has a smaller screen and, though the image is sharp, everything looks small and fiddly.

I know that cathode ray tubes wear out but I always thought that flat screens don't because they don't get hot.