my imac 27" 2014 dead

1. Check the power cord on the back of the iMac.
2. Check/have the wall outlet checked by an electrician.
3. Follow the steps, at > https://support.apple.com/en-us/HT204267

Try this: unplug the iMac from the power socket.

Press and hold the power button for 3 seconds.

Release and plug power cord back into the socket.

Turn on.

This sometimes resets the entire system and overcomes a power supply overload / glitches.