Hi, I have at the moment a 4 GPUs rig, 4 ATI Sapphire HD 7950. Everything was working fine until few days ago: after a reboot of the rig, I could only see 3 GPUs in cgminer, and the same in the device manager. I tried to remove each GPU one by one to find the one with a problem. Once I got it, I tried to plug it on different PCI-e port, but nothing happened (I still couldn't see it in my device manager).

Do you think the card is dead or should I test something else?

Thank you.