I have a PC1553 home security system with a wireless module installed. Last night, the alarm went off, and I was unable to disarm the alarm by entering my code. All I saw was the system light. When I entered my code, sometimes the panel would give the normal "beep" when pressing buttons, and sometimes it did not. I resorted to unplugging the transformer from the wall. This morning, I plugged it back in, and I can see the system light illuminated, and I hear a long beep about once every couple of seconds. I tried pressing *2, but no lights illuminate. If I open any of the contacts the alarm goes off.
Anyone have any idea what might be wrong? The board was replaced about a year ago.