Light Intensity Adjustment - Ricoh FT7770 Service Manual

30
April, '89

4. Light Intensity Adjustment

ADJUSTMENT STANDARD:
1. Clean the optics, the toner density sensor, and the charge corona
wires.
2. Check/adjust uneven exposure and horizontal magnification.
3. Position the exposure switch [A] to the darkest position and select ID
level 4 [B].
4. Place the test chart on the exposure glass and make 15 copies (A3/LDG) to
stabilize drum sensitivity.
5. Select ID level 2 [C], and make 3 test copies.
6. Confirm that the test copies are within specifications.
NOTE: If you have no test chart, place 2 or 3 sheets of pure white copy paper
on the exposure glass, and make 3 copies. In this case there should be
no background on copies.
7. If the test copies are not within standard, adjust the lamp regulator out-
put using SP 35 and repeat steps 5 and 6.
8. Adjust the auto density sensor as the sensor output voltage will be changed
by the above adjustment.
NOTE: Adjust lamp regulator output voltage to 70 volts using VR2 if the
lamp regulator board is replaced.
When the exposure switch is set at the
darker position and the 2nd level of the
density control is selected, level 0.2 on
the standard test chart should be slightly
visible on the copy and there should be no
background on the copy.
(Refer to Auto Density Sensor Adjustment.)
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