| Symptom | Most likely causes | First checks |
|---|---|---|
| Weak stick on larger rod | 120 V limitation, hot connector, bad clamp | Verify voltage class and current path |
| TIG complaint only | Torch, gas, or setup issue | Prove stick first |
| Arc unstable | Heated connector, weak return path, poor utility | Inspect hot points |
| 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.