Please help! My MacPro desktop suddenly shuts down without any warning!

[MRC127]

Hi everyone! I am reposting this in attempt to get more advice and support on my issue.

I purchased a pre-owned Apple Mac Pro 2,1 this past December. I mainly use it for editing my photographs on Adobe PS, using RAW camera filter. The unit never gave me any issues, until earlier this week. Here are the specs:

- 8-CORE 3.0Ghz (2x Quad-Core)
| 32GB RAM | 250gb SSD | GTX-680 4GB V-RAM

- El Capitan and Yosemite on two separate boot drives.


It all began with an error screen regarding the GPU, when I opened a CR2 file on PS. Shortly afterwards, the Mac suddenly shuts down without any warning whatsoever! No messages, no sounds from the tower itself, and as the power light remains on. I then turned the power off. I waited for one minute, and turned it back on again. At the password screen, it would shut down again.

I then let the machine rest, performed some minor troubleshooting, and other "light tasks" to prevent a system overload..... The problem still occurs within 35 minutes of turning the machine on.

Again, I unplugged everything (including the power cord) to reseat the two riser boards. I powered the Mac with the access panel open, to keep an eye out for anything unusual. All fans are running smooth, no signs of any problems. Until I tried to update the GPU driver, the machine shut down again! I then discovered, a red light (as pictured). After I powered the unit down, the red light was still on. I then turned off the surge protector, the light turned off.

I have no clue what to do next. Can anyone here please provide any pointers, help, and/or advice. I greatly appreciate it!

Matt

 

[DeltaMac]

You could tell us which LED is lit.
There's 8 LEDS in that area, all in a line. 4 of those would be red, if switched on by a hardware condition.
There's 1 for either CPU A or CPU B errors (FAIL), and 1 for each CPU in an overtemp (OVERTEMP) condition.
The logic board has clear labeling on the board for each LED.

 

[MRC127]

You could tell us which LED is lit.
There's 8 LEDS in that area, all in a line. 4 of those would be red, if switched on by a hardware condition.
There's 1 for either CPU A or CPU B errors (FAIL), and 1 for each CPU in an overtemp (OVERTEMP) condition.
The logic board has clear labeling on the board for each LED.

DeltaMac, thank you for pointing that out. I am a first time Mac owner, still learning more about how it works.

I managed to get a better closeup shot of those LEDs. I am assuming that the description, that it is overheating?

 

[DeltaMac]

You can check if the CPUs are actually overheating, in addition to the overheat LEDs. There's several utilities that you can download that will show you the output from the various temp sensors in your MacPro.

But, there's this note, from Apple's MacPro 8-core service manual:

If both overtemp LEDs come on immediately when the computer is turned on, a faulty power supply could be one cause of this behavior. Replace power supply.

(my bold type)
The likelihood of BOTH CPUs overheating at the same time is less likely than a possible problem with the power supply, particularly when the manual points that out...
But, you should also check that temp ranges are reasonable for the CPUs.
You may want to reapply the heatsink compound on an 8 or 9-year old Mac, just on principle...

 

[MRC127]

You can check if the CPUs are actually overheating, in addition to the overheat LEDs. There's several utilities that you can download that will show you the output from the various temp sensors in your MacPro.

But, there's this note, from Apple's MacPro 8-core service manual:


(my bold type)
The likelihood of BOTH CPUs overheating at the same time is less likely than a possible problem with the power supply, particularly when the manual points that out...
But, you should also check that temp ranges are reasonable for the CPUs.
You may want to reapply the heatsink compound on an 8 or 9-year old Mac, just on principle...

DeltaMac, thank you for pointing that out. I didn't think of the heat sink compound, do you happen to know how or where to apply it by chance?

Also, I managed to download a tempature monitor, within the small window of time before the automatic shutdown; The results are in the attachment.

I did notice that the Northbridge Heat Sink shot up quite fast within the five minute when it was on. I tested it by opening Photoshop, where it hit 76 degrees Celsius before it shutdown again.

Thanks!