yes
what I found out from EPLUS owners posts here and on TF forum, other forums that people would randomly plug, unplug communication /small round plug/ and power connectors back and for when Eplus was powered. BIG NO, NO.
Motor electronics has inverter and this has capacitors, pulling out or pushing in power connector with battery voltage present causes spikes which can destroy example DC /DC converter.
As I told him first before opening motor comm cable must be checked for continuity , inside comm cable black, white, orange wires must be checked all the way to display/controller.