Well if the power supply doesn't pass the paper clip test when it's outside the computer...then it's the power supply.Also, the Antec Basiq 500W is the bare minimum required to run that vid card, in your system.
This is from the specs for an EVGA GTX 670
Minimum of a 500 Watt power supply. (Minimum recommended power supply with +12 Volt current rating of 30 Amps.)
FYI, single rail power supplies are better than the cheaper multi rail power supplies.
IF you have to replace it, I would suggest...
http://pcpartpicker.com/product/h3FXsY/evga-power-supply-220gs0650v1 <--- This power supply has a single 12v rail that can handle 54 amps.
/e
http://support.antec.com/support/solutions/articles/1000015319-is-my-power-supply-dead-the-paperclip-testAlso, the power supply does have a 3 year warranty, so if it's less than 3 years old, you can RMA it. I would just replace it if I were you.
This post was edited by Ghot on Jul 26 2016 11:41pm