Strange shutdown problems

[CaveJohnson]

Wondering if someone can help me here. Lately (within the last week) ive been having sudden and unexpected shutdowns. The best way to explain it is as if my computer power button was held down without me knowing (it isnt). Its that kind of sudden. I had a friend try and help me figure the problem out, but there are no crash reports he could find and the only dump file that was saved mentioned my gpu. I updated my drivers, but the problem persists. I thought "maybe my computer is overheating" but Ive checked each seperate part, all have working parts, the gpu never breaks 35 degrees C, cpu was fine when stress tested, and Im just lost for what to do. I thought "maybe its because of League of Legends" which is running 80% of the crashes, but after contacting support and doing what they said, nothing has changed. Ive done security scans to check for bugs or viruses, got nothing. I just dont know what to do anymore.

Specs:
Msi Motherboard
Cpu: FX-4100
Gpu: RX-480
Psu: 750w corsair gold

 

[bignastyid]

Most common causes are overheating and power issues. Posting the system specs incl;uding make and model of the PSU would be helpful with troubleshooting.

 

[CaveJohnson]

I edited in specs for the pc

 

[bignastyid]

Which MSI motherboard? They have a few AM3+ boards with thermal issues.

 

[CaveJohnson]

Well, I looked up my motherboard specs...and it came up as "Not available"

 

[bignastyid]

MSI usually prints the model on the board. CPU-z will also usually show the model.