Chosen Solution
I have led light 1 on, which i know is trickle feed, so that’s fine. I have tested the voltages on the power supply, but they don’t change when i depress the on button on the imac. i have put in a new power supply and get the same result. is the second power supply dead as well or is it a fault with the logic board? thank you for any help
Use a multimeter and test the output of both.
