As Alex asked, what happens when you roll the card with a working DNIC from 1 or 2? Does the problem follow the card or the slot?

Also, what happens if you lift the jumper and connect the phone at the MDF? (this will eliminate wiring as a cause).

Distance may be an issue, especially if the wiring is 28 gage or smaller, or if there are moisture/corrosion issues at IDFs (look for green snot on the 66 blocks). Check the Technician's Handbook for recommended distance/gage.

You also might have two phones sharing a DNIC port (miswire issue).