iMac not waking up


macrumors 6502
Original poster
Jun 11, 2010
Just developed a fault on my late 2012 27" iMac after I've not used it for a few hours it switches off and I have to turn power on and off at the plug or pull out power cable then hit the power on button at the back to strat the iMac. Anyone had this problem or know what could be the issue?

Thanks in advance