6M controller, (Matsuura 760 VDC) with a 400 Servo alarm. Called Fanuc and the response was so vague, "Could be anything" they said. No alarms on drives, swapped all the top cards and base units, cables all intact, megging the servo motors now but they seem fine. Cannot figure this one out. 30 years in the business, I love my Fanucs, but this one is kicking my tail! Any ideas out there? (also a 4th axis on machine, Tsudokomo) Thanks so much.