Just an update on this problem...I can't get ANY phone to work on ports 5 thru 7 on this card (Slot 8). I swapped it out with a known good DTIB card and still the same. I added a known good DTIB card to Slot 9 and none of the ports work. When I plug a 3515-71 to any of those bad ports, I get correct time and date and "OK SYNC" and some other characters, but none of the buttons work and no dialtone. Bad expansion cabinet or motherboard in main cabinet (even though everything seems to be working fine off the main cabinet)??