Computer won't boot with new 560 Ti

HoustonBones

Honorable
Feb 19, 2012
3
0
10,510
After 4 years I decided to upgrade the graphics card in my machine. Motherboard is an Asus Striker II Formula nForce 780i SLI Mainboard (Socket775) with 3x PCI Express x16 slots (two of which support PCIe 2.0 devices). My old card is a NVIDIA GeForce 8800 GTX 768MB 16X PCI Express and the new card is a Nvidia GeForce GTX 560 Ti. I'm running Vista 64 bit on my machine.

I swapped out the cards and when I booted up my machine with the new one, I get one long beep and 3 short ones (cannot detect a VGA card or VGA card test fail). I double checked all the connections and tried again, but no luck. When I put my old card back into the slot (the one closest to the CPU), it now would not work either (same beeps).

After trying both cards in all 3 slots, the only time the machine will sucessfully boot is when either card is plugged into the middle PCI slot (the one that doesn't support PCIe 2.0 devices). With the new card in, I went ahead and installed the drivers but whenever I launch a game, my machine locks up.

Any advice on why neither card will work in the PCI slot the old one was in would be appreciated. I checked both the cards and the motherboard for damage but couldn't find anything obvious. I was pretty certain the new card was compatiable with my older machine but perhaps it isn't.

Thanks
 

HoustonBones

Honorable
Feb 19, 2012
3
0
10,510
My PSU is 750W versus 500W required by the card, so I should be good there. I made sure to hook up both 6 pin power cables to the card.