This information same for the HP Z2100 Designjet printer
1st Call 4 Service was called out to repair a HP T770 Designjet printer with error code 47:01 in Manchester but this could happen various printers in the range of Designjets
Star Wheel bail arm was not moving up or down due to Star Wheel Motor (one of three gear broken off) this is a complete unit which was replaced.
Firmware only for the below models
Firmware TTAJ_07_00_01.2 was supplied with Star Wheel Motor for HP T770 Designjet and HP T1200 Designjet.
HP must of updated firmware due to this issue?