PC randomly shuts down

[DubZeroSP_1]

Ahead of time I am just gonna say thank you for taking the time in reading this and helping!

As said in the title my PC turns off randomly, but it only happens while playing games in the past 2-3 days, only while playing Starcraft 2 (It could be a ladder match or campaign, it makes no difference), it doesn't turn off at a specific point in the game, nor after set amount of time - it just happens(temps are fine and below 65-70°C and I have disabled the option that turns the PC off if it gets over a certain temp in BIOS) When it turns off, the screen says "no signal", but for a few seconds I can still hear dialog/in-game SFX and then it completely turns off and I am greeted with the boot screen.

I don't know if it's connected, but whenever something using the HDD like downloads, file transfers, my PC is slowed down, not by much, but it is noticeable. Note: loading game data or watching video previously loaded on the HDD doesn't seem to be affecting it...

System specs:
PSU: CoolerMaster 500W
CPU: Intel Core 2 Quad Q9550 2.83GHz
GPU:RX 470 4GB Nitro OC
RAM: 8GB
MOBO: BioStar G41D3+
HDD: Toshiba 500GB HDD (x2)

Again thanks for taking the time and helping me!

 

[ArchitSahu]

Which model PSU? This points directly towards a PSU failure and CM did not make the best PSU's for quite some time.

 

[DubZeroSP_1]

Which model PSU? This points directly towards a PSU failure and CM did not make the best PSU's for quite some time.

I don't know what specific model it is - it just says "CoolerMaster 500W"

 

[ArchitSahu]

Most likely a poor unit. Find a friend with a well rated PSU to test out your PC or buy a new, well rated and sufficient wattage PSU.

 

[DubZeroSP_1]

Most likely a poor unit. Find a friend with a well rated PSU to test out your PC or buy a new, well rated and sufficient wattage PSU.

Will try that and post when I've tried it and got the results