The Valcom V‑2003AHF is a three‑zone integrated talkback/page control that provides telephone systems with one‑way paging or two‑way handsfree capability and includes built‑in steady, warble, and alert tones as well as background music input. Common failure points for this type of unit include the internal power supply (often a 12 V DC regulator), the tone generator circuitry, and the speaker/microphone connections; degradation of the printed circuit board traces or solder joints can also cause intermittent zone operation. First‑check diagnostics should verify that the supplied voltage matches specifications, inspect all wiring for continuity and proper polarity on the speaker and microphone terminals, and review any error codes or status LEDs displayed on the front panel.[oss-gpt-20b]