Hello,
Just got my new 390 Strix to replace the GTX 770 I had before and I noticed that between 2000-3000 rpm the center fan causes grinding noises. I checked the fan cable to make sure it does not touch the fan blades, and it does not. I will monitor the card in the next few weeks to see if it gets worse. If it does, I might have to RMA the card, would it be possible to get hold on the fan itself as a replacement part? I'll try to record a video with the fault and unfortunately I didn't expect that this fault gets past quality control.
Best regards from Slovakia.