Oki LP-1040 Maintenance Manual page 543

(2) Two circuit board configuration
1.
Perform the first procedure of 10.1.1 Primary
Charger Load Current Calibration on p.
10-2 so that the front power supply unit is
visible.
2.
Insert the digital multimeter's terminals into
the high voltage power supply unit's CH4 and
GND terminals. Then activate the separator
bias by going to Test -> DC CHECK in
Engine Maintenance mode (see 2.3.10 Test).
Measure the AC load voltage effective value
Vdca.
Note:
Set the digital multimeter's measurement
range to AC to measure.
3.
If calibration is required, rotate the CH4
adjustment volume with a screwdriver for
voltage calibration.
CH4 adjustment volume
Setting range: 8.25 to 8.75kV
Ideal value: 8.5kV
CH4 terminals
(digital multimeter reading = 2.9 to 3.1V)
P-P
(digital multimeter reading = 3.0V)
P-P
Chapter 10 Printer Calibrationt
10-11