Try the monitor on some other PC and come back.
I plugged the monitor in without connecting to a PC. The same problem occurred. The self-test graphic came on for about ten minutes and then the screen went black. When I immediately turned the monitor off and on, the picture came back for a couple of seconds before going out. I did this repeatedly. After leaving it off for ten minutes, the picture came back for about 15 minutes.
Does it seem that something is overheating?