Ricoh Aficio 220 Service Manual page 298

20 September 1999
SC322: Laser synchronization error
-Definition- [B]
The main scan synchronization detector board cannot detect the laser
synchronization signal for more than 5 consecutive 100 ms intervals.
- Possible causes -
• Poor connection between the laser synchronization detector board and the
BICU board
• Laser synchronization detector board out of position
• Laser synchronization detector board defective
• BICU board defective
• LD unit defective
SC324: LD drive current over
-Definition- [B]
The LD drive board applies more than 100 mA to the LD.
- Possible causes -
• LD unit defective (not enough power, due to aging)
• Poor connection between the LD unit and the BICU board
• BICU board defective
SC390: TD sensor error
-Definition- [B]
The TD sensor outputs less than 0.5V or more than 4.0V 10 times consecutively
during copying.
- Possible causes -
• TD sensor abnormal
• Poor connection of the PCU
SC391: Development bias leak
-Definition- [B]
A development bias leak signal is detected.
- Possible causes -
• Poor connection of the PCU
• High voltage supply board defective
SERVICE CALL CONDITIONS
7-5