Mac pro 5.1 shutdown randomly

hi Guys,

i need help with my Mac Pro as I already did a lot of research on net and nothing helped...

i have a Mac Pro 5.1

12 core 2.93

32gb of ram

Gtx 970 (now running a gtx 120 for testing purposes)

2 ssd for OS (mac and windows)

i most usually for 3dmax and autocad on windows bootcamp

it starts 4 months ago with randomly shutdowns, and become more frequently.

On windows, gave me BSOD with WHEA error code. First I reinstalled windows and hold for 3 weeks without shutdown. After started again, I swapped the gpu and tried MAC OS, but it shutted down too randomly. So I run hardwares test and everything was fine.

the shutdown become more frequently at the point that it stay on sometimes only for 10 min and restart....

I already swapped all memories, cleaned everything inside, reset SMC, check Northbridge plastic rivet, applied new thermal paste on all 3 cpu And install a fan control to check the temperatures and control fan speed. It seems to hold it for some more time but after a while it starts again... the temperatures seems to be ok as I saw in a lot of posts, but what get my attention, was that the heatsink B and memories (1-4) were extremely hot to touch but the sensor on fan control not shows nothing extreme....

I brought it to Apple authorized (as on my city don’t have apple store) and they said it was the logic board (easiest answer) without doing any test, just because the higher temperature to touch and justifying that they don’t have any part of this mac to swap for test purposes...

so my last call, was running ASD, and it gave me only one error (attached).

can you guys help me on this? Is the psu or cpu board the problem?