Troubleshooting458 Service Instructions 755 A/756 A - 00.0 - 02/20193030 Sewing motor: Phase error • Test sewing motor phases(R=2.8 OHM, high impedanceto PE)• Replace encoder• Replace sewing motor• Replace control3040 Mains voltage drop Check mains voltage3100 Control voltage:Temporary mains voltageinterruptionCheck mains voltage3101 Power voltage:Temporary mains voltageinterruptionCheck mains voltage3102 Voltage sewing motor:Temporary mains voltageinterruptionCheck mains voltage3103 Voltage step motors:Temporary mains voltageinterruptionCheck mains voltage3104 • Pedal not in rest position• Setpoint device defective• Do not press the pedal whenstarting up the machine• Replace setpoint device3107 Machine temperature• Ventilation openings closed• Ventilation grille dirty• Check ventilation openings• Clean ventilation grille3108 Speed limited due to insufficientmains voltageCheck mains voltage3109 Safety stop active Switch the Safe stop off3121 • Compressed air missing• Compressed air insufficient• Turn on compressed air• Stabilize compressed air3123 Oil level too low Top off the oil p. 4403210 • Thread broken Insert thread3220 • Empty bobbin Change bobbin3500 • Error Command Interpreter• Motor synchronization Internalerror• Switch off and on the machineagain• Perform software update p. 431• Feedback to Dürkopp AdlerServiceError code Symbol Meaning Remedial action
