The L‑Tec PCM‑7501 is a 3‑phase (460 V) industrial plasma cutter that uses an internal power supply to drive the arc and air‑flow control circuitry. Common failure points on this class of units include overheating of the high‑current transformer, degradation of the MOSFET/IGBT driver board, and failure of the air‑pressure regulator or its solenoid valve; these can manifest as no‑arc, erratic cutting, or intermittent power‑on behavior. First‑check diagnostics: verify that the 460 V input is present and stable, inspect the main transformer windings for insulation breakdown, and confirm the air‑flow sensor/valve operation by checking pressure readings and solenoid continuity.[oss-gpt-20b]