MRCC 880 Bad Din1In?

[pbreitz]

I'm using a brand new MRCC 880 out of the box, plugged into USB power (no computer).  After some tinkering around, I discovered that nothing plugged into Din1in seems to work, but the trs port does (with the right adapter). Before I return to my retailer, is there anything I should try to get the DIN port working?