Clean OS install from both High Sierra and Mojave
Set and reset all cables and connectors
Found a “button on the control board" (not documented but very near the SMC chip) see attached picture (purple circle) *not documented in the public sphere. — nothing seemed any different after pressing it and or pressing it and holding it.
Current State - Both Mac Pros (one with the 12 core cpu and one with the factory 4 core) boot but are severely CPU throttled and fan running at full speed. Neither are really usable. There must be something missing that this would happen across two nearly identical computers.
Ran Apple Diagnostics results with the following errors - Reference Code PFM006 and Reference Code PPN001 — Both of which say “There may be an issue with your power management controller (SMC)
Any and all help really appreciated.
Have tried the following:
Down grade CPU (no change)
Reset SMC (the apple way and also the rEFIt/rERInd way)
Several attempts at different amounts of thermal paste
Several different CPU bracket tightnesses- less tight and the way it comes from the factory (bracket arms all the way to the logic board). *** in the OWC video method, you will have trouble replacing the PowerSupply unit because the CPU bracket screws will be too high. There seems to be some disagreement about what is either even possible or recommended based on the they original state)
Another thing I’ve noticed is that PRAM “zapping” doesn’t work nor do simple things like software reboot or shutdown. As if the SMC really isn’t able to do what it is supposed to do. When I do a restart the system will either shutdown (and not reboot) or just flip back to the login screen. Also when you power on then hold the Command - Option - “P” & “R” keys it just shuts down but not reboot.
A run-down of things I’ve tried.
Environment - At the start.
2 Mac Pro 2013s
1 - 4 core 3.7MHZ, 2 TB SSD (Feather M13-S SSD) 128 GB RAM
1 - 4 core 3.7MHZ, 256 GB SSD (Factory OEM) 12 GB RAM
Both were working just fine prior to CPU upgrade attempt
After CPU upgrade the following symptoms:
Fan running at full speed. (using a fan control program is not a good option - see below)
Kernel Task taking up all of the CPU resulting in super slow response.
After Downgrade back to factory CPUs the same issues persist.
Apple Diagnostics show Reference Code PFM006 and Reference Code PPN001 — Both of which say “There may be an issue with your power management controller (SMC)”
Following Apples posted instructions for SMC reset doesn’t do anything.
Additionally, I’ve gone the the trouble of replacing the CMOS battery as well. Still no change.
Hello. I’ve been trying to get this upgrade to work for a few days. I end up with a system where the fan is running full speed and a “kernel task” is taking up almost all of the CPU. After reading about the CPU and kernel task it seems as though this is a way for the CPU to protect itself. A throttle so to speak. Everything was running well until the upgrade and even a subsequent downgrade back to the original CPU picks up the same issues. I’ve tries PRAM resets and SMC resets. Neither change the CPU/kernel task issue. Is there a missing step? Some sort of reset that needs to be done?