My PSU is seasonic focus gold 850w, It have fanless mod. Today when I turn fan on, It start having some kind of clicking sound. When I set my fans to 600 rpm and just read webs, then clicking sound are noticeable and annoying. But when I set my fans to 900 rpm, and then play PUBG, the clicking sound are negligible. The same sound was heard when I play diablo 3 without turn psu fan on, but the clicking sound are intermittent. I thought It was came from graphic card. But the sound are really similar, now I believe it came from psu as well. I have no idea why. So do I need to return or exchange my psu?