I have a tuner card also, a Hauppauge card.
A coax cable does not transmit sparks normally...if you have what appears to be a coax cable and it has live wire properties...I'd have to say that's an issue that needs to be taken up with someone.
OTOH...maybe it was your system that was creating the apparent short with the metallic coax...hard for me to say from what you write.
Checking the card accomplishes nothing, since the card was of no consideration when the apparent short happened.
If...whatever created the short...doesn't exist any more...nor does your former power supply...I'd have to guess that this is not just coincidence.
I'm not sure just what you want anyone here to comment on...