This has happened a few times now. While idle, one of the fans just spontaneously starts up by itself and will keep spinning at medium speed until I either reset the profiles in GPU Tweak or shut down the PC. It does this well below the 55c threshold the fans normally start at, most recently the card was at 40c when It turned itself on. When it does this the fan speed reads as 0 in monitoring software.

Anyone know why it's doing this?