Ricoh D093 - Controller Startup Error; PER Command Error; Sc700; VDB Communication Error

Service Call Tables
SM 7-31 D093/D094
Trouble-
Shooting
672 D Controller startup error
CTL
After power on, the line between the controller and the operation panel did
not open for normal operation.
-or-
After normal startup, communication with the controller stopped.
 Controller installed incorrectly
 Controller board defective
 Operation panel harness disconnected or defective
687 D PER command error
The main machine received no PER-command module from the GW
controller.
 Poor communication, cycle the machine power off/on
690 D VDB communication error
There was no serial communication with the VDB within 1 sec. after power
on.
 VDB-to-MCU harness or connectors broken, loose, defective
 VDB defective
 MCU defective
7.3.7 SC700
There are no SC700 level SC codes for this machine.