I was mining for one week stable at 72-76 celcius, 720 khash per card then one of the card dropped to 300 khash in hash rate. Fan slowed down, and temp crashed too. I decided to reboot.. Same thing.. then suddenly zero in hash rate.

Bamt now doesn't recognize it after a couple of reboots.

Same slot, same powered riser with another 280x and it work wells. So card seems in fault.

Did I fried a card?

If so, what do I say to the retailer in order to get an RMA?