Screen goes black and fans go 100%

I saw one post with this type of problem and it was unresolved, so I have to post a new one. Every time I try to play a game my screen goes black and all the fans go to 100%. It happens randomly, sometimes after 10 minutes, sometimes after 2 hours. I suppose it’s the PSU. Specs RTX3070ti 8gb, 3 fans so it needs some power r5 1600 AF (I need to replace it, but have no funds) 600W BeQuiet Pure Power 16gb 3200mhz ram altogether 3 140mm fans