Ricoh C249, Service Manual

Page: 276 / 486

MASTER FEED
C264 3-20 SM
Standard Value
Master present
Threshold level (SP6-51)
Standard Value
Master not present
2.0
±
0.1V
2.8V Above 3.3V
3.5.8 2ND DRUM MASTER SENSOR ADJUSTMENT
Ensures that the sensor detects if there is a master on the drum.
Standard: 2.0 volts (within “+0.1” and “-0.1”volts)
Tools: Circuit tester
•
Rear cover ( 3.2.2)
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 (2.0 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.
[A]