Dead Imac With Replaced Power Supply And Logic Board Won T Power Up Imac Intel 27 Emc 2429

Chosen Solution

iMac 27 mid 2011 failed suddenly overnight after working perfectly. Will not power up at all. No fans, No chimes, Nothing. Shows only one LED on Logic Board Checked cord, outlet, power button etc. Replaced Power supply - shows one LED, No sign of power Replaced Logic Board - shows one LED, No sign of power. Replaced Hard Drive - no change. Disconnected Optical Drive - no change. Suggestions… or should I give up?

Install a KNOWN GOOD power supply.