Ricoh A-P4, Service Manual

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3. Replacement and Adjustment
Precautions
General Precautions
• To avoid damage to the transfer belt, drum, or development unit, never turn off the power switch while
electrical components are active.
• Always turn off the power switch and unplug the machine before attempting any of the procedures
in this section.
Laser Unit Precautions
1. To avoid putting the LD unit out of proper adjustment, never loosen the screws that secure the LD drive
board to the laser diode casing.
2. Never adjust the variable resistors on the LD unit, as they are adjusted in the factory.
3. The polygon mirror and F-theta lenses are very sensitive to dust. Never open the optical housing unit.
4. Never touch the glass surface of the polygon mirror motor unit with bare hands.
5. After replacing the LD unit, do the laser beam pitch adjustment. Otherwise, an SC condition will be
generated.
• Always dispose of used toner in accordance with local regulations.
• To avoid a serious fire hazard, never expose toner to an open flame.
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