Alarm A.100, a failed power stage and fans barely turning: industrypart inspected, repaired and completely overhauled this Yaskawa Servopack SGDV-550A01A002000. After repair and thorough cleaning, the unit was tested with a motor.

Nameplate data

Reported fault: A.100

The unit arrived with alarm A.100. The manufacturer associates this code with overcurrent through the IGBT or an overheated heat sink. It provides a starting point for diagnosis but does not identify the failed component on its own.

Workshop findings: power stage and gate-drive electronics

Our inspection identified failed transistor modules in the power stage. Several semiconductors in their drive circuitry were also defective. The repair therefore had to cover both the power modules and the affected drive components.

Contamination and inadequate cooling

The unit was dirty. Deposits had also accumulated on the fans, which were barely turning. In our workshop assessment, the inadequate cooling had contributed to the electronic damage. The available information does not establish an exact temperature or a detailed sequence of failure.

This is relevant to maintenance: clean airflow paths and functioning fans are part of the inspection alongside the electronics. Cleaning alone does not repair an already damaged power stage.

Complete overhaul and motor test

We repaired the power stage and affected drive circuitry and carried out a complete overhaul. Components covered by our standard preventive overhaul for this unit were replaced. The fans were renewed and the Servopack was thoroughly cleaned.

The unit was then tested with a motor. The footage below documents that test after repair; it is not presented as evidence of a load or endurance test.

Selected alarm references

Only A.100 was reported in this case. The other codes below are general Sigma-V references, not additional faults recorded on this unit.

Yaskawa Sigma-V User’s Manual, SIEP S800000 45, section 10.1, pp. 10-3 and 10-10. Cross-checked against the supplied German alarm extract, pp. 10-3 and 10-10.

Motor test after repair

Repair photographs

Repair enquiry

Please send the full model, a nameplate photograph, the alarm display and a description of when the fault occurs. industrypart supports you with diagnosis, repair and preventive overhaul of industrial drive electronics.

Yaskawa Servopack SGDV-550A01A002000

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