How to troubleshoot when the D6412 or D4412 panel will not release the phone line.

[#1]

When the panel dials out it will not release the phone line when it stops dialing and hangs up:

• Check the resistance across the tip house and the tip and the ring house and the ring to ensure they have 0 ohms of resistance. 
• If there is not 0 ohms of resistance the connection is open and the panel will keep the line seized.