Computer boots up first time after inserting new graphics card. Does not boot second time

[ravenshrike]

This is a fun one.

 

970A-G46 motherboard, latest drivers.

 

Old graphics card is dead. New one is an xfx 8gb rx 480

 

Antec EA-650 watt power supply and all games play fine on first boot.

 

No anomalies on board lights or POST error beeping.

 

After the second startup, no Bios, video, or hard drive activity.

 

If I remove the card, boot the computer, shut down, reinsert card, and boot again it starts right up, everything working again.

[homeap5]

Looks like PSU or mainboard problem.