B. Adjusting The Transfer Charger Current - Sharp SF-2030 Service Manual

B. Adjusting the Transfer Charger Current

1 Remove the developing unit, transfer/separation charger unit,
main charger unit and waste toner bottle from the machine.
2 Remove the processing unit from the machine.
When removing (attaching) the processing unit, do not grasp the
toner feed pipe.
3 Remove the photoreceptor drum from the processing unit and
mount the electrode sheet on the drum using adhesive tape.
4 Install the photoreceptor drum into the processing unit and at-
tach the processing unit to the machine.
5 Attach the drum holder unit to the machine in the manner which
allows drawing the lead of the electrode sheet from the
developer tank side.
6 After cleaning the transfer charger wire, attach the trans-
fer/separation charger unit to the machine. (Do not attach the
main charger unit).
7 Connect the electrode sheet to the digital multimeter (or an
ampere meter).
Manually turn on the door switch.
8 Measure the drum current on the sides of front and rear frame.
The difference in current between the front and rear frame must
be 5.0 µA or less.
a. Turn on the main switch and perform Simulation "8-06".
(THVG will be ON for approx. 30 seconds)
b. Measure the drum current on the front and rear frame side.
•
If the microswitch is OFF, the drum current on the side of
front frame is indicated.
•
If the microswitch if ON, the drum current on the side of
rear frame is indicated.
(OFF)
N/C
N/O COM
c. Check that the difference in current between both sides is
5.0 µA or less. If the difference is more than 5.0 µA, replace
the charger unit.
9 Adjust the THVG output voltage:
a. Turn on the main switch and perform Simulation "8-06".
(THVG will be ON for approx. 30 seconds)
b. Use the THVG output control VR201 to adjust the THVG
output voltage until it becomes –42±4 µA.
(ON)
N/C
N/O COM
Note: Make sure the black clip is grounded at the machine chassis.
7 – 4
Yellow clip
Black clip
Machine chassis
(uncoated part)
black
blue
2
(DCmA)
2 0
2 00
Blue clip
Digital multimeter
(UKOGE0043FC01)
When using UKOGE0043CS01:
Control 1: set to DCmA
Control 2: set to 2
Red clip : connected to
Blue clip: connected to $
When using a d.c. ampere meter:
Red clip : connected to $ of d.c. ampere meter
Blue clip: connected to
Green clip
orange
orange
white
Microswitch
white
red
Red clip
⊕
⊕
of d.c. ampere meter