Hi, Try turning the monitor off at the mains for a few minutes and then turn it on. can you hear any clicks or anything at all when turning on? If so then power is reaching the monitor. Try it on another PC. Try pressing the switch on monitor on & off a few times, it could be that the switch on the monitor has gone. (cheap to repair) Test that your fuse for the monitor plug is ok, if you don't have testing tools like an Ohm meter or test screwdriver then substitute fuse for a known good one. Try another monitor on your PC to make sure your video card is working ok. it could have been unseated from it's socket. Unless it's built in video wHich you can tell by looking at the back, if the video connector is horizontal in one of the expansion slots then it's a seperate video card, if vertical next to serial port and down from it, it's built in and can't become unseated. It's just a matter of narrowing it down to either the video card itself or the monitor, and if power is reaching it or not.
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