MP 1,1-5,1 My Beloved 5,1 May be Dead - Where to begin diagnosing?

[Don_Con]

I've had this 5,1 since 2011 and it has served me so incredibly well. I did all the relevant upgrades through the years and eventually got it to its current state of Running Mojave and hardware specs of (100% due to this forum and all the great help I've received):

2x3.46 Ghz 6 Core Intel

128 gb of 1333 DDR3

Radeon RX 580 8gb

I planned ahead and luckily transitioned to a new workstation and also a Home NAS so this 5,1 was primarily just a back up machine I'd turn on once a month a so to find older files or emails that were archived.

Fast forward to today, I went to turn it on, and the only thing that happens is I hear a very soft/muted "click", about 75% of the sound/feeling I normally get when I turned it on, and NOTHING happens.

No power up, no hard drive spin, no fans turn on. When I try to hit the power button again, I do not hear anything. When I unplug the machine, and plug it back in and try the same power on, I get the same muted click, but nothing boots.

I'd like to keep it alive but I am lost where to begin troubleshooting?

 

[tsialex]

There are several threads here that you can read and learn how to diagnose a dead Mac Pro. Long story short, the fastest way to do it is to get a known working Mac Pro and test one component at a time.

From what you wrote, the PSU seems the most probable failed component. DIAG button shows anything?

 

[Don_Con]

There are several threads here that you can read and learn how to diagnose a dead Mac Pro. Long story short, the fastest way to do it is to get a known working Mac Pro and test one component at a time.

From what you wrote, the PSU seems the most probable failed component. DIAG button shows anything?

Thanks will search, and it doesn't boot up enough for me to get a response out of the DIAG button approach.

 

[tsialex]

Thanks will search, and it doesn't boot up enough for me to get a response out of the DIAG button approach.

You don't even need to power up to use the DIAG button… You need to identify what the lit LEDs are showing, Apple Service Manual around page 28 to 33 have the description.

 

[Don_Con]

You don't even need to power up to use the DIAG button… You need to identify what the lit LEDs are showing, Apple Service Manual around page 28 to 33 have the description.

I tried holding down D and then Option D during boot up, nothing.

Then turn everything off, unplugged everything, replugged in power cord. Then held down power button for 10 seconds, same symptoms.

Am I missing something else for DIAG attempts?

 

[tsialex]

I tried holding down D and then Option D during boot up, nothing.

Then turn everything off, unplugged everything, replugged in power cord. Then held down power button for 10 seconds, same symptoms.

Am I missing something else for DIAG attempts?

You are mixing the Apple Hardware Test diagnostic software that the factory installs to the main disk of the Mac Pro with the HARDWARE DIAG circuit located right back/below the PCIe fan area on the backplane. Download the Apple Technician Manual for your Mac Pro model year and open the pages that I've written above.

Btw, Apple Hardware Test is only present if you still have the factory installed disk from when the Mac Pro was new and it wasn't ever formatted. So, it's very improbable that you still have it…

 

[Don_Con]

You are mixing the Apple Hardware Test that the factory installs to the main disk of the Mac Pro with the HARDWARE DIAG circuit located right back/below the PCIe fan area on the backplane. Download the Apple Techncian Manual for your Mac Pro model year and open the pages that I've written above.

Btw, Apple Hardware Test is only present if you still have the factory installed disk from when the Mac Pro was new and it wasn't ever formatted. So, it's very improbable that you still have it…

Ah yes, was confusing those two.

And yes, that disk no longer available.

I'll start with swapping the PSU as the most likely entry point.