Chosen Solution
After installing a new AC/DC power supply, when connecting the power cord, the diagnostic LED #1 comes on briefly and then turns off. Disconnecting and reconnecting the power cord returns the exact same result and for what appears to be the exact same time. The LED doesn’t flicker, rather gives a good steady one second illumination before going out. Thinking I had possibly installed a faulty power supply, I replaced it with a second new one yet the results are the same. As I understand it, LED #1 Indicates power has been detected and should be illuminated whenever the iMac power cord is plugged in whether the unit is on or off. If LED #1 indicates that power has been detected, why would it come on and then methodically turn off? It’s as though power is being detected long enough for some secondary system, switch or fuse to shut it off or cause it to trip. Any help or suggestions would be appreciated.
