ASUS Z97-A last PCIE 2.0 x16 slot not working?

[fleshconsumed]

So I just got ASUS Z97-A motherboard for my main desktop. To keep it short the motherboard has three x16 PCIe slots. The top one is currently occupied by R9-290 and the last, bottom most PCIe x16 slot was supposed to hold my ASUS Xonar STX sound card. Here's the problem, no matter what I do I cannot get the bottom most PCIe 2.0 x16 slot working. I have tried plugging ASUS Xonar STX sound card in that slot, intel network card, they won't work. I even plugged in a spare nVidia 210 video card I had laying around thinking maybe that slot requires full length card to work, but no. No matter what I plug into that last slot, windows will not see it. I tried the middle PCIe 3.0 x16 slot, and that one works, but the bottom one just won't work no matter what I do.

I have spent half a day putting everything into the case because of the various clearance issues, and it's driving me nuts to think that it has been all for naught. Before I start return process with newegg, can anybody think of any reason why the last bottom most PCIe slot will not work? Is there maybe a physical switch on the motherboard? A BIOS setting? Or maybe it's designed to work this way? Please help, I'm at the end of my wits here...

 

[MongGrel]

It says on the MOBO description that the PCIe 2.0 X 16 slot is default disabled.

Have never had that board, you probably need to look around the BIOS a bit more than anything right now, to try to enable it.

"1 x PCIe 2.0 x16 (x2 mode) *1
*1: The PCI Express 2.0 x16 slot shares bandwidth with USB 3.1. The PCI Express slot is default disabled."

Relax and take a deep breath a bit, I've been there before myself

Might even be a jumper somewhere, but I would think BIOS.

 

[fleshconsumed]

Yeah, thanks, I just discovered that myself while painstakingly walking through every BIOS menu option.

Man, I can't believe how much time I've wasted on this crap, and I can't believe I have to lose the 3.1 ports on the back if I want to use that 3rd PCIe slot. Wish I knew that before I bought this board. I'm strongly tempted to just return this to newegg and get ASRock Z97 Extreme4 instead. Sigh...