Hi,I am new to this forum,so please go easy on me. I have a Mitel 3300 and ASU in my school.We were able to release our electric strikes on our doors by dialing 9 and a three digit code on the phone. It has stopped working and when you dial the code now you get a busy signal and the screen on the phone says out of service. I believe we are using analog ports for this and any ideas where to look in the system to figure out whats going on would be helpful. I am NOT very knowledgeable so any help please explain in stupid person terms,Thanks