Saeco royal error msg: Grinder blocked - but the grinder is not blocked:)

[JMDB]

Wonder if anyone could help us.

1)The grinder is clearly not blocked but 9 times out of 10 it won't operate and we get the message "Grinder Blocked".
1) What could cause the grinder not to operate? are there any other upstream switches beside the door and /onoff switch?
2) How to test grinder motor for defect?

Thanks in Advance

Royal Saeco Redesigned.

 

[JMDB]

Thanks. I'll try to remove the motor to inspect it. Anyone knows how to free the motor/grinder assembly from the rubber bushings which hold it the base?