Question Screen goes black for a few seconds while gaming. Is my GPU failing or is it my PSU?

Apr 12, 2019
Hello, I'm new here so sorry if I'm posting in the wrong place.
I have a very old Dell XPS 8300 with a core i5-2300 and 8gb RAM. I put an Inno3d GTX 1060 6GB in it for a cheap gaming PC. It worked for a few months but now while gaming, I get a black screen for a few seconds multiple times during the playthrough. I can still hear sound and still control my character. This happens in graphically intense games. I want to know if this problem is caused by a failing PSU or is my GPU faulty? I suspect the PSU as it's a very old one. It's the OEM power supply that came with the Dell and is rated for 460 watts. I bought this machine used so it's a pretty old machine.
I would like to mention that the CPU and GPU temps are fine. GPU temps go up to 75-80c while gaming but I live in a very hot place. (30-35c weather)
Thank you in advance.