4 x Gigabyte 280x rig riser issue

[orpington]

My 4 x Gigabyte 280x rig has a weird issue.

card 1 directly on mobo ( GA-990FXA-UD5 )
card 2 on 16x to 16x unpowered riser
card 3 on 16x to 16x unpowered riser
card 4 on   1x to 16x    powered riser

When configured as above everything works perfectly.

If I put card1 on a 16x to 16x unpowered riser to get it off the mobo that card still works but suddenly card4 is no longer recognized.

Whats the deal?

I want that card off the mobo.

Any ideas? 

[Mineraholic]

Try using powered riser on 2 cards.

Do you got a psu with single 12V rail?

[orpington]

Single rail EVGA 1300 G2

So you think 2 on powered and 2 on unpowered?

[Mineraholic]

That's worth a try, because it would be similar to your working setup with card 1 directly on mobo.