| Symptom | Most likely causes | First checks |
|---|---|---|
| Weak or erratic weld | Low branch voltage, extension-cord loss, poor clamp | Test on dedicated circuit and clean clamp point |
| Wire feeds poorly | Liner drag, wrong tension, bad tip, spool drag | Remove tip and compare feed |
| No weld output | Bad clamp path, loose internal or output path, burnt tip | Check clamp, tip, and trigger/feed response |
| Breaker trips | Shared branch or undersized extension cord | Remove extension cord and retest |