Xerox Phaser 7760 - Page 420

January 2010
2-384
Phaser 7760 Color Laser Printer
OF 99-3, OF 99-4
Revised
Status Indicator RAP’s
OF 99-3 Switch
Procedure
Actuate the Switch. The display changed.
YN
There is +3.5/+5 VDC measured between Pin 2(+) of the Switch and GND(-).
YN
Check the wire between the switch Pin 2 and the PWB Pin 3 for an open circuit and
poor contact. If the check is OK, replace the PWB.
There is +3.5/5 VDC measured between Pin 1(+) of the Switch and GND(-).
YN
Replace the Switch.
Check the wire between the PWB Pin 4 and the switch Pin 1 for an open circuit and poor
contact. If the check is OK, replace the PWB.
De-actuate the Switch. The display changed.
YN
Disconnect the connector on the Switch. The display changed.
YN
Check for a short between the switch Pin 2 and the PWB Pin 3. If the check is OK,
replace the PWB.
Replace the Switch.
Replace the Switch.
Figure 1 OF 99-3 Switch
OF 99-4 Generic Solenoid/Clutch
Solenoids and electric Clutches are essentially electromagnets. Typically, a positive voltage is
applied to one end of a coil, and a current driver is connected to the other end. Control Logic
switches this driver to GND potential, actuating the magnet. Bi-directional solenoids have a
bipolar driver connected to each end. One leg is switched to 24 VDC and the other to GND.
Figure 1 is a circuit diagram of a typical Solenoid.
Initial Actions
Ensure that there is no damage or binding in the solenoid or in any mechanical linkage. If there
is an Adjustment for the clutch or solenoid, make sure that the procedure was performed cor-
rectly
Procedure
The Clutch/Solenoid is always energized.
YN
Enter Service Diagnostics Menu: Printer Menu > Troubleshooting > Service Tools >
Printer Status Page >hold the Up and Down buttons simultaneously > Run Service
Diagnostics > OK. Perform the Clutch or Solenoid tests. The Clutch or Solenoid
energizes.
YN
There is +24 VDC between the switched leg (J543 pin A6 in the example, Fig-
ure 1) of the control PWB and GND.
YN
There is +24 VDC between the powered leg (J543 pin A7 in the example,
Figure 1) of the control PWB and GND.
YN
Disconnect the connector (J543 in the example, Figure 1). There is +24
VDC between the powered leg of the control PWB and GND.
YN
Refer to the 24 VDC wirenets. check the input power to the control
PWB. +24 VDC is present.
YN
Use the 24 VDC wirenets to troubleshoot the problem.
Replace the control PWB.
Check the wire in the powered leg of the circuit, (J543 pin A7 in the exam-
ple, Figure 1) for a short circuit to GND (refer to Section 7, Engine Control
Board (MCU PWB) Plug/Jack Locations - Figure 15). If the wire is OK,
replace the clutch or solenoid.
Disconnect the connector (J543 in the example, Figure 1). Check continuity
through the two wires and the Clutch or Solenoid. There is less than 100
ohms between the two legs of the circuit.
YN
Disconnect the Clutch or Solenoid. Check continuity through the two wires
and the Clutch or Solenoid. There is less than 100 ohms across the
clutch or solenoid.
A B C D