Sharp AR-5520 Service Manual page 20

(3)Developing bias voltage check
Note:Use a digital multi-meter with an internal resistance of 10MΩ or
more.
1) Set the digital multi-meter range to DC700V.
2) Put the test rod of the digital multi-meter on the developing bias
voltage output check pin.
3) Turn on the power, execute SIM25-1.
<Specification>
Mode
Developing bias voltage
(4) Grid bias voltage check
Note:Use a digital multi-meter with an internal resistance of 10MΩ or
more.
1) Set the digital multi-meter range to DC700V.
2) Put the test rod of the digital multi-meter on the grid bias voltage
output check pin.
3) Turn on the power.
(The voltage is outputted in the grid bias High output mode during
warming up, and in the grid bias Low output mode when warming up
is completed.)
<Specification>
Mode
Grid bias LOW
Grid bias HIGH
Specification
DC - 400±10V
Specification
DC - 380±8V
DC - 525±10V
AR-5520 ADJUSTMENT 6-2
B.Mechanism section
Note: If a jam error or paper empty occurs during copying in the
adjustment by the simulation, the image data are not saved, and
therefore recopying is required.
(1) Image position adjustment
a.OC image lead edge position adjustment (SIM 50-1)
Note: In advance to this adjustment, the sub scanning magnification ratio
adjustment must be performed.
1) Set a scale on the OC table as shown below.
2) Make a copy.
3) Check the copy output. If necessary, perform the following
adjustment procedures.
4) Execute SIM 50-1.
5) Set the OC lead edge position set value (PHOTO indicator ON) to [1]
The OC image scanning start position is shifted inside the document
edge.
6) Set the 1st tray lead edge void adjustment value (TEXT indicator
ON) * to [1]
The lead edge void becomes the minimum.
7) Set the 1st tray print start position value (AUTO, 1st tray indicator
ON) to [1] and make a copy.
The print start position is shifted inside the document edge.
*The dimension varies depending on the model.
8) Measure the image loss R of the copied image. Enter the set value
of the image scanning lead edge position (PHOTO indicator ON)
again.
•1 step of the set value corresponds to about 0.1mm shift.
•Calculate the set value from the formula below.
R/0.1(mm) = Image loss set value
<R: Image loss measurement value (mm)>
* The scanning edge is set.
(A line may be printed by scanning the document edge.)
Example: 4/0.1 = 40 = about 40
Note: If the set value is not obtained from the above formula, perform the
fine adjustment.
5mm
5
4mm
10
5mm
0mm
5
10