ha escrito:

Pci dial-up modem blocks the PC when inserted
below is the pci pinout and the card uses B/A 1-62
http://www.geocities.com/anglomont/pcipins.txt
do you think the cause is a short circuit on some of the power / other
pins?

A bad or shorted modem can block the PC. Return it to the seller or
discard it.