Sounds like you've had a bang on the machine and overloaded the servo's which drive the axis. If you smack the machine up and tool has nowhere to go the motor will still try and push it and eventually it'll cut out and usually throws out one of them servo alarms your getting.
Have a look at the Fanuc manual and go to the alarms section to see what it actually is and how to get rid of it. I've had this a few times and it sometimes can be solved by disconnecting the Z axis lead from the mainboard in the back of the machine then reconnecting it.
Good luck
