Ricoh K-C3.5L Service Training page 67

ID sensor
TD sensor
Slide 67
More on 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 SP 2221.
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 SP 2925. If the machine detects the TD sensor error condition 10 times
consecutively, an SC code is generated (SC390) and the machine must be repaired.
Abnormal Sensor Conditions
If ID sensor output is out of spec, machine disregards
output from sensor, and uses a Vref of 2.5 V.
After replacing ID sensor, reset error counter with SP
7-992.
If TD sensor output is out of spec, machine changes
to fixed supply mode 2.
» Toner supply motor on always for 200 ms per page
Copying continues until a TD sensor error is detected
10 consecutive times.
Then SC 390 is generated and machine cannot be
used.
67
Model K-C3.5L