Last night was pretty odd. My 770 was acting up, I was thinking that the overclock I tried on core damaged the card. If I put load to the card, the display stops working, the monitor says no video input, and the fans on the 770 spin at 100%
After a hour of testing different games, GPU stress with MSI kombustor, different drivers, and re-sitting the card, the blame was the power cable. I used one of those 1 to 2 2+6 pin cables to power the card. Swapped it out for 2 cables instead, and the card works just fine now. I was actually pretty excited to upgrade my card, to some like a R9 390x.
The cable actually had a hard time coming out from my AX760. After a while, it came out, but one of the plastic covers for the pins actually broke off. It's inside the psu cable connector. Now I'm considering the PSU to a problem with the plastic inside of the connector.