Ricoh FACSIMILE FAX77 Field Service Manual page 120

Item
Step
2 Flatness
Procedure
In the oscilloscope waveform,
(A-B)/A must be less than 0.25. If it
is not, do the following.
1. Access the SBU as explained in
"Preparation" above.
2. Set the oscilloscope scale to 0.2
V/unit (vertical) and 0.5 ms/unit
(horizontal).
3. Connect the oscilloscope probe to
XVIDEO (pin 1 - blue wire) and the
ground to GND (pin 4 - black wire)
on the test lead.
4. Light the xenon lamp (see page 2-
24).
5. Remove any test charts that are on
the exposure glass.
6. Loosen the shading plate securing
screws [A].
7. Move the shading plate [B] back
and forth until the waveform meets
the requirements.
8. Tighten the shading plate securing
screws.
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