Try the usual million mile work. Remove power, deep clean, fresh heatsink compound under all heatsinks, replace bad fans and then re-test. The 650 was a power hog so it may need a fresh PSU. If it still fails, you often find yourself changing motherboard and CPUs.
At first I thought it might just be the power supply but I bought a new one and it is still doing it. So I did a clean install of Windows in case it was a virus but it continues to power off.
Processor AMD FX(tm)-8320 Eight-Core Processor
Motherboard: MSI 760GMA-P34 (FX)
Speed 3.5 GHz
Number of Cores 8
Video Card NVIDIA GeForce GTX 650
Memory 8.0 GB
Operating System Microsoft Windows 10 (build 10240), 64-bit