2Nd Drum Master Sensor Adjustment - Ricoh DD 4450 Service Manual

Master Feed

4.7.9 2ND DRUM MASTER SENSOR ADJUSTMENT

Ensures that the sensor detects if there is a master on the drum.
Standard: 2.2 volts (within "+0.1" and "-0.1"volts)
Tools: Circuit tester
Rear cover ( p.4-10 "Rear Cover")

1. Check that there is a master wrapped on the drum.
2. Connect the terminals of a circuit tester to TP104 and a grounded place (e.g. iron base)
3. Connect the power plug, and turn on the main switch to access SP mode.
4. Select SP6-53 (2nd drum master sensor voltage) and press the master-making key.
5. Measure the voltage with the circuit tester, and turn VR104 until the value becomes between
"-0.1" and "+0.1" volts from the standard value (2.2 volts).
6. Turn off the main switch, then remove the master that is wrapped around the drum and install
the drum in the main body.
7. Turn on the main switch to access SP mode.
8. Select SP6-53 (2nd drum master sensor voltage) and press the master-making key.
9. Check if the value of the voltage becomes below 0.8 volts.
10. If the voltage is not correct, clean the black patch [A] on the screen.
When the voltage cannot be adjusted to the standard value, adjust the threshold level of

the 2nd drum master sensor. (SP6-53: 2nd drum master sensor voltage)
Standard Value
Master present
2.2V+-0.1V
C279
Threshold level (SP6-53)
1.0V
4-46
Standard Value
Master not present
Below 0.8V
SM