Toner Supply In Abnormal Sensor Conditions; Id Sensor; Td Sensor - Ricoh B039 Service Manual

DEVELOPMENT

6.9.7 TONER SUPPLY IN ABNORMAL SENSOR CONDITIONS

ID Sensor

Readings are abnormal if any of the following conditions occur:
• Vsg ≤ 2.5V
• Vsg < 3.5V when maximum power (979) is applied
• Vsp ≥ 2.5V
• (Vsg – Vsp) < 1.0V
• Vt ≥ 4.5V or Vt ≤ 0.2V
The above ID sensor values can be checked using SP2-221.
When this is detected, the machine changes the value of Vref to 2.5 V then does
the toner density control process (in a similar way to sensor control mode 2).
No SC code is generated if the ID sensor is defective.

TD Sensor

The TD sensor output is checked every copy. If the readings from the TD sensor
become abnormal, the machine changes the toner density control mode to fixed
supply mode 2, and the toner supply amount per page is always 200 ms,
regardless of the value of SP2-925. If the machine detects the TD sensor error
condition 10 times consecutively, an SC code is generated (SC390) and the
machine must be repaired.
B039/B040/B043 6-48 SM