Gigabyte 5670 1gb problem

[sifis_samos]

Hello there.. one week ago, i bought a second hand Gigabyte 5670 1GB to replace my Nvidia GT240 in mymain rig.. I Installed it today, but there seem to be some problems.. It gives me random artifacts, especialy when i play any video.. if i open youtube for example my pc freezes instantly.. well i realize that it is a faulty card, but just to eliminate any mistakes i tried to play in the bios.. before i had pci-e freq set to auto..i resetted it to 100Mhz but now my computer doesnt even see the vga and says that there is an error in my display adapter...

so what do you think? should i throw it away or there is something else to try?

[bluetooth]

reset your system to system defaults.
uninstall all vga drivers; reboot; reinstall new graphics driver.

[sifis_samos]

i already did that pal.. so i assume it is faulty card..