MP 6,1 Mac Pro 2013 won't turn on

[naujoks]

I have a Mac Pro 2013 which was working fine until today, when on booting the WiFi mouse wasn't working.
I held the power button pressed to power down the machine.
When trying to restart it, the fan won't spin up and there's no boot chime. The only sign of life is the lights at the back coming on, staying on for 15 seconds and then go off again.
What could be the problem?

 

[bax2023]

1st step - unplug everything except keyboard, moinitor and power and do the NVRAM and SMC reset.

 

[naujoks]

NVRAM Reset is Option + Command + P + R? How do I do the SMC reset?

 

[naujoks]

One thing I noted is that all lights at the back are lighting up, except the power button itself.

 

[bax2023]

NVRAM Reset is Option + Command + P + R? How do I do the SMC reset?

There are detailed instructiond in the links of my original reply.

 

[naujoks]

Yes, I see that now.
I did the NVRAM reset (no change), but the SMC reset it simply unplugging it for a bit and then turning it back on?

Desktop computer
If your Mac isn't a laptop computer, follow these steps:
Shut down your Mac, then unplug the power cord.
Wait 15 seconds, then plug the power cord back in.
Wait 5 seconds, then press the power button to turn on your Mac.

Either way, I did that and it still doesn't work.
I read that a run down SMBIOS battery might be the reason for the fault, so I swapped that for a new one, although the old one was at 3.06V and probably fine.

 

[naujoks]

I've tried the PSU from another Trashcan and also swapped the CPU.
Same result.

 

[bax2023]

I've tried the PSU from another Trashcan and also swapped the CPU.
Same result.

Are you in position to swap I/O boards ?

 

[naujoks]

Yes. When I said I swapped the PSU, I meant the whole PSU/IO assembly.

 

[bax2023]

Then all points to the circular logic board at the bottom (661-7527)

 

[naujoks]

I've swapped the logic board for a known good one too now.
Same problem.

 

[bax2023]

So, you have cleard NVRAM, reset the SMC, swapped PSU, I/O board nad Logic Board, and its still the same problem ?

You could try with different, 100% good RAM modules before going to CPU board and after that I'm out of ideas. There is no reason to suspect on GPUs or NVMe with those symptoms.

 

[naujoks]

That is correct. I've swapped the CPU as well.
So really the issue can only be with the CPU board. But why should that break all of a sudden?

 

[StoneJack]

That is correct. I've swapped the CPU as well.
So really the issue can only be with the CPU board. But why should that break all of a sudden?

who knows? 10 year old computer box can break any time. Time to move to newer machine.

 

[dtelena]

Hi, I am on the same boat. Exactly the same symptons and I have tried everthing too: swapped PSU, I/O board, CPU, memory, etc. even changed the BR2032 battery for a new one... the only thing I haven't swapped is the circle logic board and the CPU riser card (the one that contains the CPU itself and the RAM slots) so I guess the problem must be in one of these cards but how should I know for sure which is the faulty one? It doesn't make sense that a computer doesn't turn on (well sometimes it does turn on, sometimes takes several minutes to turn on and in most cases it doesn't do anything at all so looks like random pattern) due to any of these two boards I haven't swapped, right? or are they?

I have ran ASD several times and every time the results are the same: NO issues at all !!!