Master End Sensor Adjustment - Ricoh DD 4450 Service Manual

4.7.10 MASTER END SENSOR ADJUSTMENT

Ensures that the sensor detects the end mark (a solid black area) on the master roll.
Standard: 1.8 volts (within "+0.1" and "-0.1" volts)
Tools: Circuit tester, the core of a used master roll (the core has no master)
Rear cover ( p.4-10 "Rear Cover")

1. Connect the terminals of a circuit tester to TP101 and to a grounded place (e.g. iron base).
2. Put a piece of master [A] on the used master roll.
3. Place the core of the used master roll inside the master-making unit, and close the
master-making unit.
Insert the core so that the piece of master [A] faces towards the master end sensor.

4. Connect the power plug, and turn on the main switch.
5. Measure the voltage with the circuit tester, and turn VR101 until the value becomes between
"-0.1" and "+0.1" volts from the standard value (1.8 volts).
Please refer to the following table for the standard voltages.

If the voltage cannot be adjusted to the standard value, do not change the threshold

level using SP6-50 (Master end sensor voltage).
When set a new roll
(master present)
Above 3.0V
SM
Standard value
Master end (4 layers of
master on the core)
Below 2.0V
4-47
Master Feed
End mark only
Below 0.8V
C279