Yesterday i updated Sierra partition to High Sierra 10.13.5. I also updated Nvidia Driver.
After this update my Mac Pro can't go to sleep, but turn off with a red led flash 1 time.
My Mac Pro is a 6 core 3.33Ghz with Gtx 780. I have Adobe CC and my Sierra boot SSD (Samsung 850) is on a OWC Accelsior S.
Thank you for your reply.Could be a Firmware thing or SMC thing. Is the SMC on the two boards the same? Try to update them. Or more easy thing would be to strip the machine down to its original configuration and work from there. Take an old HD and do a clean install of Sierra, where as High Sierra is not final.