Chosen Solution
changed the EFI chip (firmware lock) on my iMac and now it won’t boot. Symptom is LED1 on, LED2 flashing every 5 seconds. The PS seems to be ok, I can measure 12V getting to the logic board. Power button does nothing. Before I start looking for shorts, etc, wondering if the new chip is either bad or fried during installation.
No it won’t boot without its firmware load.
