Recently added a second GTX 660 Superclocked to my rig for SLI Bridge. About 2 days ago, I started getting blank screens, with no BSOD. I talked to EVGA Support, and they recommended that I look at the 12V rail. According to my Motherboard (Asus M5A99X EVO R2.0) I have a dips as far as 11.132V on that rail. Should I replace the PSU?
I think you should at least start with telling us what model of PSU you are working with.
Having said that I can't really offer anything regardless but 11.1v does seem like it might be outside of the voltage tolerances for hardware. Tell us what PSU it is and maybe someone can offer something more insightful than "I dunno, maybe".