Big problem computer only boots with my old 8800 card

[superman099]

I have 2 8800 cards, one is a new 8800GT 512 from gigabyte and the other is an old 8800GTS 320mb from EVGA...now i shut down my computer today and when i went to turn it back on, nothing would happen, it turned on and all the fans wereon but it would not post and i couldn't even seen the bios. I tried my old 8800 card and it turned right on...I then took the card that wouldn't boot and checked it in my brothers computer which is almost identical to mine....it works fine...I really would like to use my new card but i can't seem to figure out why in the hell it works on my brothers computer and all the sudden, not on mine...

Specs: q6600, 4x1gig ddr2 800 ram, gigabyte p35-s3l mobo

any suggestions would be great, im desperate at this point

 

[San Pedro]

Try again, maybe it wasn't seated properly.

 

[merlin3791]

You didnt forget to plug in the power to the card did you?

 

[Guest]

the problem is your computer is smart enough to know that going from a gts 320 to a gts 512 wasn't worth it...

JK

but try the above two posters suggestions

also try the new card in another computer or a friends, its possible the card is just a dud