One external Valcom 1030C speaker connected to PA extension/ Found defective speaker. Replaced with same model but when I page I hear ring tones instead of voice over speaker. Tried moving PA to a different extension port but trouble followed it. Did a cold restart and re-programmed system but problem remains. Changed Valcom power supply and completely rewired speaker from KSU and power supply to speaker. Polarity is correct on T&R and power. Tried reversing polarity for kicks but trouble remains. I'm thinking a bad KSU. Any suggestions?