GTX 980 Strix isn't working… help?

[Ashhh]

Okay so I had one gtx 980 Strix card then I bought 2 more but one wasn't showing up in SLI so I tested them all individually and one doesn't display anything despite the fans spinning and the power lights on

Anyone know what might be causing this?

[Chino]

Try using a different video output for testing.

[Ashhh]

I only have hdmi so I guess I need to go to the shops