I just replaced the main paging amplifier on the system. The Dukane console works in making All Page and individual room callups. However there are 2 telehphones on an old pbx that were supposedly working before the amp blew but I keep getting a busy signal when accessing the extension for the Dukane system off of the old pbx. When I plug my butt set into the phone jack on the MACS Central unit I get a fast busy signal, both on and off hook. Another tech did a cold start on the console before I was sent to the site and made the blown amp diagnosis, so I don't know if some programming was lost for the telephone access. I did activate the 8 lines in the optional adapter section of the programming with no effect. I have no documentation on the system other than a console users and programming guide.