sudden issues with PCI-E land...

[DiabloMuerto]

I got my 2nd gtx 580 in today and now it seems I'm getting issues with the pci-e x16_1 slot on my mobo.  The x16_1 slot is the default slot for this particular board and it is the slot I have been using all this time prior to getting the 2nd card in today; it has given me no problems prior to now.  For some reason, when I put a card in there now, it fails to register.  When I power on the system, the fan just spins at 100% (sounds like) and I can tell the system is booting properly by the codes on the board but it won't show on the monitor (b/c of the card not working).

If tested both cards by themselves in the x16_2 slot and they work fine, so it's not the cards.  I then put one in the x16_1 slot by itself w/o the other card installed and I get the issues mentioned above.  I'm still in the process of trouble shooting this but wanted to post about it to get some opinions going while I work on it.  Again, the slot that is giving me issues is the slot I've been using all this time w/o any problems, when I put the 2nd card into the x16_2 slot today and powered up, that's when these problems started.

board: gigabyte GA-P67A-UD7-B3
PSU: AX1200
CPU: 2600k
windows 7 ultimate 64 bit

[Dark Mantis]

Hi

Well as you say it is the default slot for the GPU and is where you would expect to install the first card. I would recommend making sure that you are using the latest BIOS update and then clearing the CMOS following these instructions.

Remove the power cable from the mains supply and then press the power switch on the case for a few seconds just to drain any residual energy in the PSU capacitors.

Once done remove the motherboard battery for at least one hour before replacing it.
 
Next plug back into the mains supply and boot.
 
You will now need to enter the BIOS by pressing DEL and load Optimised BIOS Defaults.

Make any other changes to the BIOS settings to suit your self like disabling the floppy drive, disabling the full screen logo and making the HDD the primary boot device and then press F10 to save and exit.

[DiabloMuerto]

Thought I had a licked for a minute here.  I had it to where both cards were reading (not connected with sli bridge) so I thought I had it fixed.  Somewhere between shutting the pc down, putting the back panel on and putting on the sli bridge it's back to messed up again.  After doing those 3 things, when I powered up it's giving me the issues again, not sure why. 

Gonna work on it a bit more before clearing CMOS

[Dark Mantis]

It would sound from your explanation of what happened as if there could be a faulty connection of some description.

[DiabloMuerto]

Got it running now, so far so good...thanks all for replies!

[Dark Mantis]

Was there any reason why that you could see or was it just purely a totally unknown cause ?