dead modem?

[admin]

You need to determine the pinout of your serial port. I am not sure what exact Mac you are using. Have you tried a different terminal program? Maybe you have corrupted terminal software or a config file for it?

I offer a lifetime warranty on the electronics that I make, so I don't mind swapping this out with another one. It seems best right now to try to get the loopback test verified to make sure your Mac hardware is ok.