The system was initially set up with 4 lines and 3 extensions. We have since purchased another phone. From the block that the phones are connected I ran wire to Extension 303, but the phone is dead. Yet when I connect the same jack to 302 or 301 it works fine. I have gone through the PC program, and the manuals to see what I am missing, but have not figured it out. If someone could give me some suggestions on what to try or do I would really appreciate it. Thanks KIM