There are several contact points to check.
All drive box related (A4 power supply). Somewhere in this contact chain, a contact failure at start ocurrs.
Motor Thermostat
Relays K1, K2
Relay LPR and its contacts
Relay 1M
Associated contacts on LPR and Line Contactors.
Also at TB-1 42-41 (N.O. and 41-40 N.C.) are K1 and K2 contacts respectively.
Check every accessible terminal screw point for loose wires and terminal blocks and relays, as well as your ps operational voltage.
You can google your drive and see the manual for full diagrams.
