Black Screen.....What's going on here?

I’ve been having a weird issue with my PC. It randomly goes to a black screen while I’m browsing the internet or doing other light tasks, but the system doesn’t completely shut down — the CPU and GPU fans keep spinning. I have to do a hard reset to get it working again.

What’s confusing is that it never happens while I’m gaming or doing anything intensive. I’ve already tried reinstalling Windows, but that didn’t solve the issue. Temps seem normal and nothing is overclocked.