Gestetner B070 Service Manual page 1025

Tech Service Bulletin No. B070/B071 – 011
WHAT HAPPENS DURING AUTO PROCESS CONTROL
Auto Process Control is performed in the following order (Steps 1–5).
Step Item Purpose
Drum To calibrate the
1
potential drum potential
sensor sensor so that it
will correctly
calibration
detect VD and
VH in Steps 3
and 4.
2 ID sensor To adjust Vsg to
adjustment within the target
range for Vref
calculation in
Step 5.
3 VG To determine the
adjustment VG (grid voltage)
that will be used
during
copying\printing.
This is necessary
as the sensitivity
of the OPC
surface can
change when not
used for an
extended period,
and because the
charge casing
and grid plate
can become
dirtied.
CÓPIA NÃO CONTROLADA
What Happens
The machine applies –200V then –
700V to the OPC surface, and the drum
potential sensor takes readings both
times.
Adjusts Vsg to within 4±0.2V.
Adjusts VG until VD falls within -
800±20V.
CÓPIA NÃO CONTROLADA
SC Issued Related Display
If Fails SP
SC310, 311 SP3902-7: VM200
SP3902-8: VM700
SC353, 354 SP3001-1: ID
Sensor PWM
Setting
SP3103-2: Vsg
Initial
SC312, SP3902-2: VD
313, 315
SP3902-4: VG
SP3902-9: VD
Correction
Reference
Comments
Manual Page
P6-67
P6-68
P6-68 VD target value is
the value of
SP2001-7
(default: 800),
plus 50V when
VD correction is
applied. (See
Note below)
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