SLI 980's not showing up at all in new homebuild

[Yeeeeeeha]

Hey community, Need a little help.

I built a new box about a month ago with a Zotac 980 and everything worked great. I do high end GPU accelerated rendering so I decided to grab another 980 to go SLI. Upon installing the card I have no video signal at all.

Here's my rig
http://pcpartpicker.com/p/8zYYzy
Intel Core i7-4790K 4.0GHz Quad-Core Processor
ASRock Z97 EXTREME6 ATX LGA1150 Motherboard
G.Skill Ripjaws X Series 32GB (4 x 8GB) DDR3-1600 Memory
Samsung 850 EVO-Series 500GB 2.5" Solid State Drive
Zotac GeForce GTX 980 4GB AMP! Extreme Edition Video Card (2-Way SLI)
Corsair 760W 80+ Platinum Certified Fully-Modular ATX Power Supply
Microsoft Windows 8.1 Pro - 64-bit (OEM) (64-bit)
Samsung U28D590D 60Hz 28.0" Monitor

Current troubleshooting history.
Cards in PCI slots 2 and 4 per manual
Flashed main board bios to latest
Flashed GPU bios to latest
Tested both cards one at a time in both PCI slots - they both work fine individually.
I'm using one "Y" split PSU cable per card so it's 8 pins to 16 pins on the card side. PSU is a single bridge so don't think I'm overloaded.
Everything boots up fine, lights on, fans spinning.
in bios I don't see anything related to SLI really that's not activated. There's a section of bios that shows all the bits on the board. When one card is plugged into either of the PCI slots it shows up. If both are plugged in neither show up. so it seems the main board isn't seeing either card when they're both in.
I tried DVI, HDMI and Displayport (which I usually run) and none of them worked.
Tried with SLI bridge and without
Latest Nvidia drivers - GTA V version
I can boot up using the Mainboard display port. In win 8.1 I can't see either card at all.
I don't know if the machine is posting on boot at all as there's no signal at all.
display port activates(?) (screen is on) but is just black then goes to power saving mode. No post
Have reset CMOS a few times - Not done jumpers or battery
tried connecting PCIe Power Connector even though manual says it's not needed - no go.

I think that's about it -

Any ideas out there would be really appreciated!

Dan

 

[Bossyfins]

Did you place the SLI Bridge?

Edit: Nevermind you did do it... Have you tried moving the cards to differnet slots? Like switching them

 

[Yeeeeeeha]

Yeah, I did swap them up and down. Can't use PCI slot 5 (even if it worked for SLI) as cards are too fat, box too short. PSU in the way.

 

[Yeeeeeeha]

Update: My IT team is talking a look. they stuck in dual GTX 680's in SLI and it works. Trying an EVGA GTX 980 in one slot with the Zotac 980 next.

 

[Bossyfins]

Yea maybe the card is defective. Have you tried the new card in the slot

 

[Yeeeeeeha]

Another updated: Both zotac cards work when used in SLI with the EVGA GTX 980.

 

[Bossyfins]

Probably a defective card. Try each card. IF one of the cards fail to boot, then replace it

 

[Yeeeeeeha]

Right - both cards work just fine.

Zotac is calling us tomorrow. If that doesn't work they're going to RMA the cards and test them at Zotac, then send new ones if necessary. keep you posted.