Ricoh FT 4015, Service Manual

Page: 178 / 229

8.2 DEVELOPMENT BIAS VOLTAGE ADJUSTMENT
8.2.1 Base Bias Voltage Adjustment
ADJUSTMENT STANDARD Adjusting VR SP Mode
DC –200
±
4 V
VRB SP9-5
NOTE: Normally, each High Voltage Supply Board spare part is adjusted in
the factory before shipment. This adjustment is not required when
the board is replaced.
+
WARNING
Very high voltage is applied from the high voltage supply unit
terminals. Pay extreme attention when adjusting the bias voltage.
Make sure that the machine is unplugged before connecting the
multimeter.
1. Remove the rear cover. (See Rear Cover Removal.)
2. Set the multimeter range to dc 1,500 V, and connect the multimeter leads
as shown.
3. Turn on the development bias using SP9-5.
4. Adjust the development bias voltage by turning VRB on the high voltage
supply board.
A219R561.wmf
COPY QUALITY ADJUSTMENT 20 December 1996
6-52