Experiencing a very strange problem with my iMac. When I shut down the Mac, I can’t turn it back on immediately. To start/turn on again, I’ll have to unplug the power cable from the wall then wait for 30-60 seconds before connecting the power cable back into the (wall) power then it will turn on. Sometimes it doesn’t start after a restart and I have to do the same thing with power. Looks like it needs some kind of power “reset”. Spoke to Apple on the phone and they asked me to try the following commands which I did but the issue still exists. Option 1: Shift+Ctrl+Option+Power for 10 seconds Option 2: CMD+Option+P+R until the second startup noise Any idea? Hope it’s nothing serious as in something to do with main circuit or motherboard. Please suggest any solution if you have come across this issue before.