Every time I boot with a single Asus GTX580 graphics card in either PCIEX16_1 or PCIEX16_2 I get post beeps but everything is fine if I use PCIEX16_3. The beeps are (I think) 1 long and 2 or 3 short beeps but they happen so fast I find it hard to count them properly. This problem has only started in the past few weeks, prior to that all 3 graphics cards in SLI were being found and shown in Windows but now only 1 card is found and showing.
I tested each of the 3 card power supply's on each of the 3 cards in all PCIE16 slots but the beeps only occur in slot _1 and _2, _3 is fine for all cards using all power connections.
Does this mean that my mobo is on the way out?
Any help to fix this problem would be greatly appreciated.
Case: CM HAF X full tower
Motherboard: Gigabyte GA-X58A-UD9
CPU: Intel Core i7 980X
Graphic: 3 x Asus GTX580 in 3-way SLI
Memory: Corsair Dominator DDR3 12GB (3 x 4GB) CMP12GX3M3A1600C9
PSU: Corsair AX1200W Professional Series Gold (Modular)
CPU Cooling: Noctua NH-D14
Operating System: Windows 7 Ultimate 64bit
SSD for the Operating System: Samsung 840 Pro 512GB SSD
Hard Disks:
2 x Western Digital WD1002FAEX 1TB Caviar Black SATAIII 7200rpm 64MB Cache 6GB/s
External Western Digital My Book Studio Edition II - 2 x 1TB drives in RAID 1 (mirrored data)
Optical Drives:
LiteOn IHAS124-19 DVD Writer SATA
Pioneer Blu-ray/DVD/CD writer BDR-205BK SATA