Graphics card not recognised by motherboard

[triumphtriple]

Hi,
Tearing my hair out and would appreciate some useful advice!
I have been trying over the last couple of days to install a Palit Geforce GTX 770 Jetstream 2GB card into my PC but get no display once the cards in and PC booted (there's power, fans are spinning). I've put the Radeon HD7770 back in for now which is running fine.

CPU - AMD Trinity A8 5600K 3.6Ghz
Motherboard - ASEock FM2A55M-DGS R2.0
8GB DDR3 RAM (1333)
Corsair VS550 PSU

The card is used but known working when taking out.
Any ideas? I'm reluctant to assume it's dead without giving it a proper try.

[bandit boy]

Have you got a another pc to try it in if it does not work in that it must be dead

[triumphtriple]

Took it to a local PC repair shop. They tried it in mine and one of their PCs, charged me a tenner and confirmed dead, thanks.
At least I know ...