Gestetner B147 Service Manual page 275

Direction Area Symptom
Sub-scan Entire Color shift on the
image entire image, and
the amount of shift
from leading to
trailing edge is
almost the same.
B147/B149/B190
Action Required
Possible Cause
Output Mode
SP mode setting Normal Paper
is not suitable for
600 dpi
the paper used.
Normal Paper
1200 dpi
4-73
Procedure / Remarks
SP Mode
SP5-993- Measure the gap between the black line and other
016 (Y) colors (YMC) using a magnification scope.
Convert the measured value from [µm] to [dots] with the
SP5-993-
following formula. Then, add or subtract the calculated
017 (M)
dot value in the SP mode.
SP5-993-
Correction [dots] = Measured value [µm] / 21.2 or 42.4
018 (C)
600 dpi mode: 1 dot = 42.4 µm
SP5-993-
1200 dpi mode: 1 dot = 21.2 µm
019 (Y)
If color (YMC) has shifted up in relation to black, add the
SP5-993-
above value to the current value.
020 (M)
If color (YMC) has shifted down in relation to black,
SP5-993-
subtract the above value from the current value.
021 (C)
Examples
• If the magenta line has shifted up in relation to black
by 40µm in 600dpi mode, add 1 to the current setting
of SP5-993-017.
Correction [dots] = +(40/42.4) = Approx. +1
• If the magenta line has shifted down in relation to
black by 70µm in 600dpi mode, subtract 2 from the
current setting of SP5-993-17.
Correction [dots] = -(70/42.4) = Approx. –2
TROUBLESHOOTING GUIDE
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