Goddoctor

Hello.

I have a problem with my newly built Asus P6T Deluxe V2 system. When I connect video card XFX GTX 260
to the first PCI-E slot, it doesn't work. The screen is blank although otherwise system seems to respond (beeps = NO VIDEO CARD) just no video output). I tried many different configurations with following results:

GTX 260 in PCI-E no. 1 - BLANK SCREEN
GTX 260 in PCI-E no. 2 - BLANK SCREEN


GeForce 9600 in PCI no.1 - WORKS
GeForce 9600 in PCI no.2 - WORKS
GeForce 9600 in PCI no.3 - WORKS

I tested each setup at least a few times in different variants and the results are repeatable. I checked everything from checklist, tried with 1 DIMM, cleared CMOS, listened the beep codes with some components removed - no hints there. Either everything works as expected or the only problem is just a blank screen. i HAVE 2 MOBOS AND 2 GTX 260 VIDEO CARD. THE 2 MACHINES HAVE THE SAME PROBLEM.

MAY U HELP ME?
I only have 7300GT and GTX260 GPUs available, no other LGA1366 MBs, RAM, CPUs to test. Given that symptoms, how can I confirm which part of my system is malfunctioning so I can RMA it? Or hints how to fix/investigate the problem further?

My setup is:
CPU: intel i7 920
MOBO: Asus P6T Deluxe V2
GPU: xfx GTX 260
RAM: 3x3 GB Corsair 1600MHz 1,65v
PSU: xfx 850W

Have to agree with Ghis where's the 9600, anyway it appears a PCI card works but not a PCI-E card.
Suggest looking in bios for video card used for boot. Should see PEG for pci-express, most default to onboard then pci and lastly pci express.