Hi, does ubuntu at least try to boot with the card installed? (does the computer get to GRUB?), or does the computer do nothing at all?
First would be figuring out if its faulty hardware or bad software. to do this, either try starting a different distro/OS, or find out which driver your card is using and blacklist it :
just add this to /etc/modprobe.d/blacklist.conf replacing "module_name" by the name of the driver it uses.