| Symptom | Most likely causes | First checks |
|---|---|---|
| Weak stick arc | 120 V limitation, bad clamp, hot adapter | Verify voltage class and current path |
| TIG poor but stick okay | Torch, gas, or setup issue | Prove stick first |
| No stable output | Hot connector or bad lead path | Inspect clamp, holder, and output connectors |
| Shuts down hot | Airflow restriction or overloaded input path | Inspect fan path and plug heat |
120 V versus 240 V and stick versus TIG accessory path.