Does the power button operate as normal? Does button feel squishy or does it provide haptic feedback?
Does the battery accept charging?
Does the battery turn on when not connected to the bike/motor-battery-cable?
Note: If it turns on when disconnected, run battery diagnostics, then check the motor-battery-cable and its connection to the motor; try a new motor-battery-cable if needed
Use the battery diagnostic program to test for any internal issues (click here for instructions)
Try a different battery that is known to be functional