PC randomly turning off

[an6dk]

Over the last month or two I have started to have problems with my pc seemingly turning off for no reason. Its often after I open something or enter a part of a game but other than that I cant tie it to any particular program. When it does happen the gpu and cpu are never overheated or under high load and I dont get a “shutting down” screen or anything. It just turns off. Any advice is desperately needed because its starting to drive me insane. 
 

Build specs are as follows: 

 

CPU: Ryzen 5 3600 (not overclocked but do have aftermarket noctua cooler installed) 

 

GPU: RX6600XT (stock settings)

 

Ram: 4 sticks of 8 gb ram running at 2133 mhz (speed as reported by task manager, they are advertised as higher)

 

HDD: 1TB Apple HDD (out of an iMac, checked using crystaldiskinfo and its completely fine) 

 

SSD: PNY CS900 500gb 
 

Power supply: EVGA 700w bronze 

 

[Awpiii]

Does the computer absolutely turn off? Or does it turn off and then starts again?

Have you checked if the PSU is overheating? What case do you have / Is the cooler pointing the right way?