asked here vast times,

1: first is fit, see it did,

2: then power, if the card uses too much power (VA watts) P= Volts/amPs  and the card needs 12v power lots.

full card model number not posted by you only the terse and weak firepro w600 

but most are all "75watts or less" and if there are no AXU jack on the top or end then there is no need for ATX12v power cables.

so the card is bad, if  dead in BIOS, and BIOS is set for enable ROM firmware, extensions then the card is dead.

rip, old card. many that old are dead. 2012 card, so is 7 year old AT THE LEAST;