Okuma OSP5020M spindle problems


I am having problems with Okuma VR40-II machining center machine has OSP5020M controller + Okuma VAC III spindle drive. Problem is following:

If I input Spindle RPM's (manually MDI or auto) Cycle and STM lights come up but no spindle rotation, no alarms on controller or Spindle drive unit. If I wait few minutes spindle may suddenly start to rotate. No orientation on tool change either. Any ideas what might be wrong? This problem came today during machine use. So its no user fault.