PC shuts down randomly during use. I need to flip PSU switch off/on to turn the computer on again.

[Adam Miramon]

Lately my PC has been shutting off randomly, complete shutdown immediately by powering itself off. In order for me to turn the computer back on, I must manually flip the PSU switch off then on. Then I can hit the power button and it turns on. If I don't flip the PSU switch, hitting the power button does nothing. Generally, I am playing video games when it happens so not sure if that is a factor here. Also, my CPU was once overclocked since it was built so that might also be a factor? I rolled it back to default settings since these problems occurred.

However, I have made sure the PSU cables are tightly plugged into the motherboard and I applied new thermal paste to my CPU and cleaned the heatsink. The entire rig is about 4 years old now.

Main Components
Motherboard: GIGABYTE 990FXA-UD5
RAM: G. SKILL Value Series 8GB
Graphics Card: GIGABYTE GTX 760 2GB
CPU: AMD FX-8320
Heatsink: Cooler Master Hyper 212 Plus
PSU: SILVERSTONE ST60F-ES 600W 80 PLUS (https://www.newegg.com/Product/Product.aspx?Item=N82E16817256071)

 

[Dark Lord of Tech]

Most likely just a failing power supply.