Xerox Phaser 7300B, Service Manual, Page: 78 / 277

2-62 Phaser 7300 Color Printer Service Manual
[Yellow] [Magenta] [Cyan] [Black] Imaging Unit
Failure
U26:
Yellow
U27:
Magenta
U28:
Cyan
U29:
Black
Troubleshooting Procedure Table
Steps Actions and Questions Yes No
1 Is the Imaging Unit installed and seated
properly? Go to step [2]. Reseat the
imaging unit.
2 Visually inspect the Imaging Unit Drum
Contact Assembly and springs.
Are the contacts damaged or dirty? Replace the IU
Drum Contact
Assembly. Go to step [3].
3 Use service diagnostics to test the CMYK
IU Sensor.
Does the sensor function correctly? Go to step [6} Go to step [4].
4 Verify continuity between the IU Sensor
Board and the Engine Controller Board at
the JODEN connector.
Y pin 9 to pin 12
M pin 1 to pin 3
C pin 5 to pin 6
K pin 10 to pin 13 Replace the
Engine Controller
Board. Go to step [5].
5 Check the wiring harness.
Is the wiring harness defective? Replace the wiring
harness Replace the Back
Plate Assembly.
6 Use service diagnostics to check the IU
Up/Down motor.
Is the Transfer Unit functioning properly
by lifting the Imaging Unit? Go to step [11]. Go to step [7].
7 Visually inspect the Transfer Unit gears
and lifting arm.
See “Transfer Unit Arm and Gear
Up/Down Movement of the Imaging Units”
on page 8-232.
The gears should lift the arm when
rotated in one direction and stop rotating.
Does the gear stop rotating when the arm
is in the raised position? Go to step [8]. Replace the
Transfer Unit.
8 Check the appropriate fuse on the Engine
Controller Board to see if it is blown.
Cyan = F5
Magenta = F2
Yellow = F3
Black = F4 Go to step [10]. Go to step [9].