I have a 750 plugged in but I haven't found anywhere where I'm supposed to connect a PWR_FAN to my mobo (P8P67 Pro). Does it come with a cable to hook that up? My BIOS settings look odd with CPU and chassis fans on but nothing in the PWR_Fan section...
I'm not sue i understand your question. Are you trying to power the fan on the Corsair 750 PSU? If so it is typically operated based on load/heat. There is no fan connection for the PSU fan. The mobo fan connections are typically for the CPU heatsink fan, the front case fan and one or two auxillary fans.
I just changed some fan connectors on my Asus P8P67 Pro yesterday and here's what I can tell you. The "power fan" connector is just another 3-pin connector that will accept any 3-pin fan. However, BEWARE: that fan cannot be controlled from Asus AI Suite II (or BIOS, but that I'm not sure aboot) and therefore runs on high RPM and annoys you with noise (that's why I took my 140mm top fan and switched it to a regular "chassis fan" 3-pin connector).
Your PSU fan will power itself from the PSU, no need for additional connectors. That said, do you by chance find your TX750 (I assume it's TX750, correct me if I'm wrong) too loud on idle?