This annex is for complaints caused by worn front-end parts that are often misread as machine or feeder failure.
Use it with:
If the machine powers up and the complaint is arc quality, start quality, or short consumable life, inspect the front end before broadening the diagnosis.
| Process | Symptom | Most likely front-end branch | High-value first move |
|---|---|---|---|
| MIG | poor start, burnback, erratic arc | contact tip, diffuser, nozzle, gun neck heat | replace tip and inspect front end |
| TIG | hard start, tungsten contamination, poor shielding | cup, collet, collet body, back cap, gas lens | rebuild torch front end and regrind tungsten |
| Plasma | no start, poor cut, short consumable life | nozzle, electrode, cap, shield, cartridge | replace consumables or cartridge and retest |