First step: For safety, please cut off the frequency converter power before doing it.
Open the left and right side covers of the converter, as show in following figures:
Second step: Power on the frequency converter and switch on power, push the green start button, check the LED indicators will be lighting or not. If one of the led indicators is on, means inner fault happened. As show in following figure.
Third step: For safety, please cut off power before doing following steps.
After power off, capacitors will discharge automatically and last approx 10 minutes. Use DCV of the multimeter to detect the capacitor discharging completely or not. The multi meter shows lower than 10V means the frequency converter has discharged completely.
Forth step: make sure the capacitors discharging completely, use multi-meter to detect the value of resistance of the plug show in following figure, from left to right in sequence, 1-2, 4-5, 7-8 and 10-11. The resistance value is approx. 5K. If you see one of the 4 times detections has lower value like following picture shows, means the module is broken.