Ricoh D131 Service Manual page 481

SC300: Image Development 1
D
SC307-00
-
D
SC320-01
-
SC324-01 D
D131/D132/D133
Charge grid circuit open
When high voltage goes to the corona grid, feedback voltage is
more than the set value 9 times. This feedback voltage is used to
update PWM for output control.

Charge corona unit defective or disconnected

Charge corona harness defective

Charge corona power pack is defective.
Development output abnormal
The high voltage applied to the development unit is detected 10
times higher than the upper limit (45%) of PWM.

Development power pack defective

Development bias leak due to poor connection, defective
connector
Development motor lock
The development motor lock signal remains high for 2 seconds
while the development motor is on.
If this SC is returned on a machine in the field, inspect the toner
supply unit coil. If the gear is not damaged, replace the coil. If the
gear is damaged, the gear shaft is probably deformed, so replace
the entire unit.

Drive mechanism overloaded due to toner clumping in the
wasted toner path

Motor driver board defective
2-14 SM Appendix