| Symptom | Most likely causes | First checks |
|---|---|---|
| Feed issue | Tip restriction, liner drag, wrong roll pressure, spool drag | Remove tip and compare feed |
| Poor arc | Wrong polarity, gas issue, dirty work, weak clamp | Confirm gas, polarity, and clamp |
| Feed but no weld | Loose lugs, bad clamp path, burnt tip | Check lugs, clamp, and tip |
| Output degrades when hot | Heated consumables or lugs | Inspect immediately after sustained load |