I just received my R3 ASUS Maximus IV. I'm running (well, trying to, at least) 2x EVGA GTX 580s in SLI, but my PCI-e x16_1 lane doesn't appear to be registering anything connected to it. Both of the video cards show up fine in the PCI-e x8_3 lane. It's just the first one I'm having issues with. Until yesterday I was using an ASUS P8P67 EVO, which everything ran peachy-keen in.
When I run a solo video card, neither one works in the PCIe x16_1 slot. My monitor just keeps spamming "no signal".
So is it RMA time, or is there something I can try/am missing?