Im interested to know whats going on here.
Ive heard of other people having this issue lately. Could it be new firmwares that are being made to stop miners ? Since the older cards never had these issues, it seems it only happens on newer batches of cards.
What new firmware you talking about? That's on RTX3060 and OP is using gtx1660s, I'm also mining with 6x gtx1660 super here on risers and no issue with fan not spinning or something like that, it can be issue with power supply, riser or motherboard, if OP have spare parts he can get to the bottom of this faster