iMac won't boot (probable bad PSU)
I have an iMac 21.5” (Late 2009 - EMC 2308) which won’t boot; completely dead. I believe the PSU is dead. I am hoping someone can confirm/refute that conclusion.
I searched for a pinout of the PSU but could find none. I followed the Apple Diagnostic workflow for “No Power; Dead Unit” with the following results at the Logic Board Test Points:
Test #1 - Pin #1 -> Pin #4 - LED #1 lights and 12vdc is detected when plugged in
Test #2 - Press PWR Button - LED #2 not lit, 0vdc at Pin #12 and no startup when power button pressed
Test #3 - Disconnected power button and tested for continuity - continuity is present
(also tried jumping PWR pins on logic board where button connects - same result)
Test #4 - Pin #1 -> Pin #11 - 12vdc present, whether or not power button is pressed
I conclude, from this, that the PSU is bad. If anyone has a pinout for this PSU (661-5299 or 614-0445) or can shed more persepective on this problem, I’d very much appreciate any insight that you can offer. In any case, thanks for the time and energy you spent reading this