Error 120 code - Gestetner Office Equipment & Supplies

To reset the SC code follow these directions:
Resetting Ricoh Savin Lanier Gestetner SC Error Code

Error code 120 is scanner home position sensor problem. If it's a recurring problem, here are some troubleshooting tips:

SOLUTION:
Turn the main switch off and on.

Check the wires between Home Position sensor and the SBU.
Fix scanner board or the SBU .
Check the wires between scanner motor and the scanner I/O board
Fix the scanner motor.
Fix the Home Position sensor.
Fix pulley, timing belt, the scanner wire,
Fix the carriage.