Sharp AR-651 (serv.man4) Service Manual ▷ View online
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AR-651/810 ADJUSTMENT
3. 5. High-voltage Adjustment
The outputs of the main charger grid bias and developer bias should be checked and adjusted when the
high-voltage transformer has replaced.
The checking and adjusting is performed in the adjustment mode “05”.
(1) Preparation
(a) Main charger grid bias
1. Take off the developer unit.
2. Connect the digital tester following the right
figure. Use a digital tester with an input
resistance of 10M (RMS value) or higher.
• Range
• Range
DC1000V
• (+) terminal Connect to the rail for the
main charger.
• (–) terminal
C o n n e c t t o t h e f r a m e
(ground).
(ground).
3. Set the door switch jig and start up the
adjustment mode (05).
(b) Developer bias
1. Install the developer unit.
At this time, keep the connector of the auto-
toner sensor disconnecting and the
developer unit releasing from the drum (L-
shaped shaft in the vertical direction.)
2. Connect the digital tester following the right
figure. Use a digital tester with an input
resistance of 10M (RMS value) or higher.
• Range
• Range
DC1000V
• (+) terminal Connect to the shaft of the
developer sleeve.
• (–) terminal
C o n n e c t t o t h e f r a m e
(ground).
(ground).
3. Set the door switch jig and start up the
adjustment mode (05).
(+)
( - )
( - )
Digital
tester
tester
(+)
( - )
( - )
Digital
tester
tester
To the rail for the
main charger
main charger
To the shaft of the upper
developer sleeve
developer sleeve
To the frame
To the frame
AR-651/810 ADJUSTMENT
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(2) Operation
Connect the digital tester as described in (1) Preparation, and perform the following procedure to adjust the
outputs.
100%
100%
A3
A
XXX
YYY
100%
A3
A
A3
[0][5]
[POWER]
[Digital keys] : Enter the code.
[START]
[Up] or [Down]: Adjust the value “YYY” to satisfy the following table.
: Adjusted value “YYY” is stored in the BC-RAM.
Return to
쩸
to enter
the other adjustment
mode.
mode.
[POWER] OFF/ON : To exit the adjustment mode.
Code No.
Current set value
쩸
<Keys to press>
<Display>
TEST MODE
TEST MODE
TEST MODE
[SET]
or
[INTERRUPT]
(3) Precautions
(a) Developer bias
Note for adjustment
Adjust the developer bias if fogging occurs over the entire image even though the main charger grid
voltage and toner density are appropriate. The developer bias can be adjusted at the setting mode (08-
861, 862, 863, 860, 859) (about 36V/10 steps), and the equivalent number of steps must be adjusted
for the main charger grid when adjusting the developer bias (08-865, 866, 867, 864, 871). However, the
following problems may occur if the developer bias is lowered too much:
• Image contrast becomes low.
• Image is patchy or blurred.
• The carrier in the developer material adheres to the photoconductive drum, causing scratches around
the cleaner.
Main charger grid bias Developer bias
Code
210
205
Adjustment value
-733±5V
-480±5V
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AR-651/810 ADJUSTMENT
3. 6. Adjustment of Scanning Section
3. 6. 1. Carriages
(1) Installing the carriage wire
Install a new carriage wire as in the following figure when it is replaced.
Adjustment of the carriage wire tension is not necessary since a certain tension is applied to the
carriage wires by the tension springs.
Note: Make sure that the tension applied to the wire is normal.
Wire pulley
Carriage wire
Bracket for Carriage-1
Idler pulley
Hook
[Front side]
Carriage wire
Bracket for Carriage-1
Idler pulley
Hook
[Rear side]
Carriage-2
Wire pulley
Carriage-2
Tension spring
Tension spring
AR-651/810 ADJUSTMENT
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(2) Adjustment of the positions of the carriages-1 and -2
a. Move the carriage-2 toward the exit side.
b.
Loosen the screws fixing the front side pulley bracket, make the A/B section of the carriage-2 touch
with the inside of the exit side frame and screw it up.
c. Put the carriage-1 on the rail, make the C/D section of the exit side frame touch with the inside of the
exit frame and screw up the front/rear side of the bracket to fix it.
B
A
Pulley bracket
Exit side frame
[Rear]
[Front]
C
D
[Front]
[Rear]
Exit side frame
Bracket
Bracket
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