Service manual

3
Step Item Purpose What Happens
SC Issued If
Fails
Related Display
SP
Reference
Manual Page
Comments
3 VG adjustment To determine
the 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.
Adjusts VG until VD falls within -800±20V.
SC312, 313,
315
SP3902-2: VD
SP3902-4: VG
SP3902-9: VD
Correction
P6-68 VD target value is
the value of
SP2001-7 (default:
800), plus 50V
when VD
correction is
applied. (See Note
below)
4 LD power
adjustment
To determine
the LD light
intensity that will
be used for
halftone areas
during
copying/printing.
Adjusts the LD light intensity until VH falls
within 260
±
20V.
SC314, 316 SP3902-3: VH
SP3902-5: LD
Power (Correction)
P6-68
5 ID pattern
creation,
detection
To update Vref
for accurate
toner density
control.
An ID sensor pattern is created on the drum
surface (exposed and developed). The ID
sensor then checks the image density of the
developed areas (output=Vsp) and bare
drum (output=Vsg), and the TD sensor
checks the toner concentration in the
developer (output=Vt). Vref is then
recalculated based on these values.
SC350, 351,
352, 340
SP3902-6: V ID
SP3103-1: Vsg
SP3103-3: Vsp
SP2223: Vt
Display
P6-69