If, after all electrical wiring and mechanical structures are verified to be in working condition (with the machine operator), the motor still doesn’t turn, you can jump into the HMI and PLC in order to follow the logic bread crumbs to figure out why the motor isn’t turning.
Having no prior knowledge of how the system was programmed, the logical path in troubleshooting is to start from the HMI button.
I will use the Siemens TIA Portal platform to demonstrate cross-referencing.