Gestetner B070 Service Manual page 330

SERVICE CALL CONDITIONS
SC316: Drum Potential Sensor Error 7 (Vh abnormal
Definition [D]
One of the following occurred:
• When adjusting the drum potential (Vh) for the process control initial setting, the
drum potential sensor detects Vh is not within the range –260 + ∆Vlref ±20V. In
this case, the auto process control value is used.
• During retries for LD power modulation to adjust the amount of light, the
adjustment was out of range (-70 to +185). In this case, the value of the setting is
used.
Possible Causes
• Drum potential sensor defective
• IOB defective
• Drum unit connector defective
• LDB board defective
• Poor drum ground connection
• Drum worn
• Laser optics need cleaning
SC317: Drum Potential Sensor Error 8
Definition [B]
At auto process control initialization, the VL detected after creation of the ID sensor
pattern is greater than 300.
Possible Causes
• Drum worn
• LD unit dirty
• Poor drum ground connection
SC322: Laser Synchronization Error
Definition [B]
The laser synchronization signal (DETP) cannot be detected by the
synchronization detector even if the laser diodes are activated and the polygon
mirror motor is rotating normally.
Possible Causes
• Laser synchronization detector harness disconnected or defective
• Laser synchronization detector is installed incorrectly out of position
• LDB board, Polygonal mirror motor control PCB defective. After the CPU
issues the LD ON command, the LD OFF signal remains HIGH and the laser
diodes do not fire
• LDB board, Polygonal mirror motor control PCB defective. After the CPU
issues the LD ON command, the LD OFF signal goes low, but the laser
diodes still do not fire
⇒
• Front door safety switches are defective.
B070/B071
CÓPIA NÃO CONTROLADA
4-10
CÓPIA NÃO CONTROLADA
Rev. 01/2004
SM