I bought a 290 on ebay with a corsair hg10 and a corair h50, but when I booted it up it showed weird artifacts in the bios. here are two videos showing it, if you have any ideas on how to fix it that would be cool https://youtu.be/RS5hJhHLsPo https://youtu.be/ESm1PwZFmj8
From what I'm seeing, that 290 is in its death throes. you bought a broken 290 good sir.
Well shit, alright I'll grab a refund then
yeah, there's should be no reason the card should be artifacting AT the BIOS. if it were happening while gaming or lets say in Windows then I would consider something else. but during the BIOS? yeah I would take a wild guess (not even a guess I'm sure it's accurate) but whoever used it, used for Bitcoin mining.
And the reason why I say that is because who ever owned this bought the stock cooler. it's not all that suitable for gaming. and bitcoin mining, most people run cards 24 hours a day while mining. so I would see the need for the water cooler. which would make sense for something like this. to keep the temps down for daily every hour, on the hour use. which will kill the card quickly.
Provided you have a decent enough PSU it sounds as though you bought a faulty card. Bugger eh..