AL-840 (serv.man6). AL800 840 Service Manual-Adjustments - Sharp Copying Equipment Service Manual (repair manual). Page 15

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1) Copy (print) defective (Insufficient density, background copy, dirt,

etc.)

2) The copy density cannot be adjusted in the proper range with SIM

46-1.

3) The photoconductor is damaged.

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JOB No.

Content

ADJ M1

Copy density adjustment

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Name

Digital multi-meter/High voltage probe

Parts code/Price rank

—

Note

Internal impedance 1000 or above,
effective value measurement
Recommendable unit:
(FLUKE 87/FLUKE 80K-40)

Name

Diode

Parts code/Price rank

VHDSV03///-1

Note

Other type withstand voltage of 2KV or
above can be used instead.

Name

Capacitor

Parts code/Price rank

VCKYQ3FB102K

Note

Other type withstand voltage of 3KV
with 1000pF can be used instead.

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1) Use a digital multi-meter (effective value meter, internal im-

pedance of 1000M

Ω

 or above).

Connect the capacitor and the diode to the tip of the digital multi-
meter for measurement. If the above condition are not satisfied,
the proper measurement of voltage cannot be made.

2) Since a high voltage is outputted, be careful of electric shock.

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Range (MIN)

–305 V

Range (MAX)

–315 V

Standard value

–310 V

Default

–310 V

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Test command (Simulation)

MODE

Normal

MAIN CODE

8

SUB CODE

2

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Enforcement
time

JOB No

Content

S 009/Ua 004

When replacing the high
voltage/motor drive PWB unit

Cycle

—

Condition

1) Print (copy) density is too

dark or too light.
Though copy density
adjustment is executed with
the Test command
(simulation) 46-1,
 satisfactory denstiy cannot
be obtained. 

2) Ghost is generated.

*

1) Connect between the power PWB and the PCU PWB, the high

voltage/motor drive PWB unit and the operation unit with har-
nesses.

2) Manually turn on the cover switch and turn on the power.

3) Execute SIM 8-2. (The developing bias voltage is outputted.)

4) Measure the developing bias voltage with the digital multi-meter

(effective value meter).

Adjust VR802 so that the output voltage is –310 

±

 5V.

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