| Drooling or stringing at the nozzle tip | Possible causeTip zone temperature too high, insufficient decompression | First checkReview the tip zone temperature and the decompression setting |
| Gate mark, flash or cold weld line at the gate | Possible causeGate zone temperature too low, or tip type not suited to the material | First checkCheck the gate temperature and the tip type–material match |
| Unbalanced filling between cavities | Possible causeManifold balancing issue or temperature differences between zones | First checkCompare zone temperatures and review the balancing |
| Residue during colour or material changes | Possible causeDead spots in the flow channel or insufficient purging | First checkReview the changeover procedure and flow channel cleanliness |
| A zone does not heat up or the temperature drifts | Possible causeFaulty heater or thermocouple, poor cable/connector contact | First checkMeasure the heater resistance and check the thermocouple connection |
| The controller raises a zone alarm | Possible causeReversed thermocouple polarity or incorrect zone assignment | First checkVerify thermocouple polarity and the zone-to-nozzle assignment |
| Plastic leakage in the system | Possible causeAssembly temperature / thermal expansion balance, tightening values | First checkReview the heat-up procedure and the assembly tightening values |