MP 1,1-5,1 Mac Pro 5,1 shutting down, I'm looking for help.

[Dnilo]

Hi,

I have a MP that shuts down seemingly random, but I can also make it happen in a weird situation, let me elaborate...

The problem started happening at random situations, while using final cut, sometimes just browsing the web, sometimes with it booting... no apparent relation between events.

Before continuing, I have to let you know that I have been building computers for the last 15 years (windows, linux), so at one point I upgraded the ram of this computer with owc ram. I have the old modules as well as the 'new' ones which were installed all the way back when it was new, lately I swapped the new with the old to see if there was an issue there, nothing, still shuts down.

I upgraded the vcard with a non-apple Radeon HD 7950, and later with a Radeon RX 590. I never had issues with those either. I have both vcards and also tested swapping one with the other, also still shuts down.

The problem started occurring after a CPU upgrade and 3 months of using it. I also have both pairs of CPU's, also tried swapping them to see if the problem was there with no avail.

One thing to note is that the newer CPU's seem to more frequently than the old ones (cannot complete a fresh Mojave install with them in), and also seem to produce more heat.

Today after trying the CPU stress test with the 'yes > /dev/null' in the terminal, testing the 24 threads the cpu's were hot but working one at 90º and the other at 80º but with no problems and no high fan speeds (measured with Macs Fan Control)... However (here comes the reason I'm here asking for help), the system shuts down whenever I send the 'killall yes' command.

It just shuts down instantly.

So, is there a way to get to the root of the problem via log or something?

I appreciate your help in advance. I know a Mac Pro problem is always a damn hassle and not easy to pinpoint.

Thanks,

Daniel G.

 

[MIKX]

Including setup info for your 5,1 cMP in your signature would be a good first step - to save having to guess.

 

[Dnilo]

Well, the MP is not mine (to put it there), but it has a Dual Hexa-Core 2.93, 48GB ECC RAM

 

[MIKX]

OK.

 

[Samford]

40% chance it is hard drive fault, often caused random crashes in my MacPro's over the years.

 

[Dnilo]

40% chance it is hard drive fault, often caused random crashes in my MacPro's over the years.

Hmm.. that's interesting.. I'll try another drive. Thanks for the info.

 

[MIKX]

1.
Have you checked the Northbridge heatsink spring rivets- shut down - remove the CPU tray

2.
What temp is the Northbridge Tdiode running at ?

3.
Are you running TWO GPUs in the cMP ?

4.
How are you powering the RX 590 ( cables ) ?

 

[Dnilo]

1.
I haven't, I'll check it asap.

2. 79º

3.
No, only one.

4.
It has what I think it's a third party PSU with the required cables.

 

[MIKX]

1.
Have you done a "Triple Happy Mac CHIME " NVRAM reset ? From a COLD BOOTUP hold down Apple key + Option + P + R until you hear the " chime " three times.

2.
What brand is the 7950 ? Sapphire ? Gigabyte / HIS etc.

3.
Is the 7950 EFI flashed ?

 

[Dnilo]

1. Oh that's new for me, never used a triple NV reset! I'll try it. (had only tried one or maybe two chimes on other macs)

2. Sapphire.

3. Yes it's flashed.


Btw, thank you for your help.

 

[MIKX]

I recommend using the flashed Sapphire HD 7970 ONLY for further tests.

1.
Which position is the BIOS switch set to ?

2.
It should be set to Pos. #2

3.
What other PCIe cards are installed and in which PCIe slots ?

4.
Are ANY of the RAM diagnosis LEDs " ON " while trying to boot ? ( next to the ram slots ) ?

 

[Macsonic]

Not sure if this relates to your problem. A friend of mine had a cMac Pro that kept on having random shutdowns. After bringing the machine to a repair shop, the problem was a faulty power supply that’s going south. Years ago I had an iMac that also kept on shutting down at random and the diagnosis was a defective power supply. Though take note the cMac Pro has an “Auto Shut Down” safety feature once your computer exceeds the power consumption limit.

 

[krakman]

Could be a faulty ram module. My mac pro would work fine but then suddenly shut down.

 

[Jake Bloom]

You could try a Linux System rescue CD/ thumb drive and boot into a Linux Memory tester. This will just write and read to all of your memory. It takes a long time to run but I have identified bad RAM modules in other hardware. I have run this on my cMP and luckily all my RAM passed.

good luck with it.

Jake

 

[Dnilo]

I recommend using the flashed Sapphire HD 7970 ONLY for further tests.

1. To position 2
2. Yes
3. no other cards are in.
4. No leds are on, but I'll double check every time it boots and report back.

Not sure if this relates to your problem. .....

I'm thinking the same, maybe it's the power supply...

Could be a faulty ram module. My mac pro would work fine but then suddenly shut down.

I think we could rule out the ram since I have swapped two sets and the problem persists.