MP 6,1 Need help to troubleshooting Mac Pro Diagnostic LED (MacPro6,1 not turning on)?

[timidhermit]

My MacPro6,1 would no longer turn on. Even the backlight on the I/O panel would not turn on when I turn the unit around. Did a blind NVRAM reset. No change. Connected power to Mac Pro while cylindrical housing is removed (with magnet attached near power button to disable the magnetic lock) in order to press the diag button on the I/O board to see the diagnostic lights.

The only light is on is #2 11V. None of the other lights (#1 & #3 to #8) are lit.

Is my MacPro truly toasted? Is this a power supply or I/O board issue? So sad.

 

[timidhermit]

Anyone? Please help!

 

[hubble35]

I repaired my mac pro for 1 year with this reconditioned power supply board and it works perfectly

 

[Rafaellf]

I’m in the same situation as you, man! (https://forums.macrumors.com/threads/mac-pro-wont-turn-on.2393011/)
I’m waiting for a new psu to see if it’ll solve the issue.

 

[oogje]

My MacPro6,1 would no longer turn on. Even the backlight on the I/O panel would not turn on when I turn the unit around. Did a blind NVRAM reset. No change. Connected power to Mac Pro while cylindrical housing is removed (with magnet attached near power button to disable the magnetic lock) in order to press the diag button on the I/O board to see the diagnostic lights.

The only light is on is #2 11V. None of the other lights (#1 & #3 to #8) are lit.

Is my MacPro truly toasted? Is this a power supply or I/O board issue? So sad.

Back in March my MacPro6,1 wouldn't power up as you describe. At the time I didn't know about diagnostic LEDs and after searching for a solution I did the least expensive thing which was to replace the CMOS battery per the iFixit guide. When I got to the battery the voltage looked okay but I replaced it anyway. When I put it all back together it powered up and has been running 24/7 ever since. I don't know if it was the battery replacement or just the act of taking it apart, cleaning it and putting it back together that cured the problem. If the battery replacement hadn't worked, my next step would have been to replace the power supply.