Adjustments; Lead Edge Adjustment - Sharp Z-21 Service Manual

[10] ADJUSTMENTS

1. Lead edge image loss adjustment
The lead edge adjustment is performed in the following cases:
•
When the main PWB is replaced.
•
When the EEPROM is replaced.
Flow Chart of lead edge and exposure adjustment
A
[Lead egde adjustment mode]
Turn VR202
Misfeed lamp lights up to
allow lead edge adjustment
Perform lead edge adjustment
with VR202
Copy exposure key ON
Copying can be performed
NG
Copy check
OK
Misfeed lamp blinks
Simulation end
Turn off the power, release short
of JP201 and JP211 on the main
PWB
Attach the seal cover to the paper
exit side, and turn on the power
End
@
To light the lamp from blinking state, the VR must be turned more
Turn off the power and remove the
seal cover in the paper exit side
than 2 steps clockwise or counterclockwise. First turn the VR
more than 2 steps clockwise or counterclockwise and check that
the lamp lights up. Then perform adjustments.
Short JP210 and JP211, and turn
on the power
Misfeed lamp blinks
[Copy exposure adjustment mode]
Cpoy exposure key ON (once)
(Auto exposure mode)
Copying can be performed
Cpoy exposure key ON (twice)
(Standard manual mode)
NG
Shift to the lead edge adjustment
or exposure adjustment simulation
•
When the power unit is replaced.
@
Even in the other cases, when the drive section or the paper feed
section is disassembled or when some parts in those sections are
replaced, check copy quality.
Use a simulation to perform the lead edge adjustment. Use the same
simulation to perform the copy exposure adjustment.
The simulation procedure is as shown below:
[Copy exposure adjustment mode]
Turn on the copy exposure key
The toner lamp blinks
Turn VR202
[Manual exposure adjustment mode]
The toner lamp lights up to allow
manual exposure adjustment with
VR202
Copy exposure key ON
Light exposure
lamp lights up and the
auto exposure mode adjustment
is performed
OK
The auto
exposure lamp blinks
Copy check
OK
VR202: Center position
Counterclockwis
For each adjustment value, ±5 steps can be adjused with the
A
center as the reference
(Turning the VR about 15 degrees changes 1 step of the set value.)
– 27 –
[Auto exposure adjustment mode]
Turn on the copy exposure key
Trouble detection
All exposure lamps blink
[Auto exposure manual adjustment mode]
Turn VR202
The auto exposure lamp lights up
allow auto exposure manual
adjustment with VR202
Copy exposure key ON
NG
Copy check
OK
Clockwise
Center