Service manual
4
Note on VD correction:
As the development sleeve accumulates toner over time, the gap between VD and VB decreases, which makes it easier for dirty background to
occur. To compensate for this, the machine increases the target VD value to -850±20V when the number of copies exceeds the value set with
SP3903-1: VD Correction Counter, (default: 200K). As a result, VD increases and the VD-VB gap is maintained. This value is cleared when the
developer is replaced and initialized.
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Confirming the Success or Failure of Process Control
Use SP3902-1 (Process Control Data Display – Auto Process Control) to
determine whether automatic process control has succeeded or failed:
• If this SP returns a “0” (OFF), auto process control has failed.
•
If this SP returns a “1” (ON), auto process control has succeeded.
!
!!
! Values that differ among Bellini models
Please note the following differences in the target values for process control parameters:
SP Mode Bellini-C1a, b Bellini-C1c, d Bellini-C2
SP2001-7: VD -970 -850 -800
SP2201-1: VB -530 -650 -550
SP2201-3: Development bias for
OHP transparencies
-530 -650 -400
SP2201-4: VBp (development bias
used when creating the ID sensor
pattern)
-280 -280 -240
Target VH
-290
±
20 -290
±
20 -260
±
20