Sorry to make my first post one asking for help...
I have a 2010 Mac Pro which won't boot and I suspect either the PSU or the Backplane has failed. The symptom is that adding a power cord and pressing the power button does nothing. No noise, no clicks, no lights: nothing.
I have followed the service guide's instructions to reduce the Mac Pro to its Minimum Configuration and plug in the power. I should see the OVTMP CPUA and OVTMP CPUB LEDs illuminate briefly, and again when removing the AC. Unfortunately neither of these illuminates when adding or removing the AC. The service manual indicates this suggests failure of backplane board or PSU. It recommends testing with a known-good PSU as the more likely culprit. Trouble is... I don't have another PSU.
Incidentally if I press on with the diagnostics in the manual, it suggests pressing the DIAG button. This successfully illuminates the 5V STDBY LED as expected. This indicates the PSU is working to some extent.
So finally, I removed the PSU and used my multimeter to take voltage readings at each of the pins on the connector. To do this I had to jump two pins to get the PSU to start up, which it did. All the pins appeared to match up with someone's hand drawn pinout found online. The PSU did make a slight ticking noise during this time, but nothing too alarming.
So what I see in front of me suggests that I need a new backplane. However what irks me is that I can't find anyone else online describing this same fault condition. Yet there are plenty of failed backplanes which manifest with the OVTMP CPU LEDs active.
Anyone have experience or ideas that could help me here? I don't want to throw good money after bad. Thanks!
I have a 2010 Mac Pro which won't boot and I suspect either the PSU or the Backplane has failed. The symptom is that adding a power cord and pressing the power button does nothing. No noise, no clicks, no lights: nothing.
I have followed the service guide's instructions to reduce the Mac Pro to its Minimum Configuration and plug in the power. I should see the OVTMP CPUA and OVTMP CPUB LEDs illuminate briefly, and again when removing the AC. Unfortunately neither of these illuminates when adding or removing the AC. The service manual indicates this suggests failure of backplane board or PSU. It recommends testing with a known-good PSU as the more likely culprit. Trouble is... I don't have another PSU.
Incidentally if I press on with the diagnostics in the manual, it suggests pressing the DIAG button. This successfully illuminates the 5V STDBY LED as expected. This indicates the PSU is working to some extent.
So finally, I removed the PSU and used my multimeter to take voltage readings at each of the pins on the connector. To do this I had to jump two pins to get the PSU to start up, which it did. All the pins appeared to match up with someone's hand drawn pinout found online. The PSU did make a slight ticking noise during this time, but nothing too alarming.
So what I see in front of me suggests that I need a new backplane. However what irks me is that I can't find anyone else online describing this same fault condition. Yet there are plenty of failed backplanes which manifest with the OVTMP CPU LEDs active.
Anyone have experience or ideas that could help me here? I don't want to throw good money after bad. Thanks!
