Troubleshooting Procedures - Xerox Phaser 4400 Service Manual

Troubleshooting Procedures

Index of Troubleshooting Procedures
Verifying AC Power . . . . . . . . . . . . . . . . .3-2
DC Power (LVPS). . . . . . . . . . . . . . . . . . .3-4
DC Power Loading . . . . . . . . . . . . . . . . . .3-6
Toner Sensor Failure . . . . . . . . . . . . . . . .3-8
Inoperative Printer . . . . . . . . . . . . . . . . . .3-9
Malfunctioning Front Panel. . . . . . . . . . . 3-11
Inoperative Front Panel . . . . . . . . . . . . .3-13
Erratic Printer Operation. . . . . . . . . . . . .3-13
Power Supply . . . . . . . . . . . . . . . . . . . . .3-14
Main Motor Assembly. . . . . . . . . . . . . . .3-15
Laser Assembly . . . . . . . . . . . . . . . . . . .3-17
Fuser Assembly . . . . . . . . . . . . . . . . . . .3-18
Registration Sensor . . . . . . . . . . . . . . . .3-20
MPT No Paper Sensor . . . . . . . . . . . . . .3-21
Tray 1 No Paper Sensor. . . . . . . . . . . . .3-22
Output Tray Full Sensor . . . . . . . . . . . . .3-22
Stack Height Sensor Checkout. . . . . . . .3-23
Verifying AC Power
There is a possible problem with AC power.
Warning: Improper connection of the grounding conductor can
result in the risk of electrical shock.
The following must be observed:
Never use a ground adapter plug to connect the machine to a power source.
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Never attempt any maintenance function that is not specifically called out in
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the service procedures.
Never remove any covers that are fastened with screws, unless so instructed
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in the service procedures.
Caution: If any of the voltage measurements are not as specified in
the following steps, the cause must be corrected. Caution
the customer NOT to connect the machine to the wall
outlet. Advise the customer that a licensed electrician must
correct the wiring. Do not attempt to correct the wiring
yourself. If you later find the condition has not been
corrected, inform your manager in writing of the improper
wiring.
3-2
Print Cartridge Sensor Assembly . . . . . 3-24
Tray Motor Assembly Checkout . . . . . . 3-26
Registration Clutch . . . . . . . . . . . . . . . . 3-27
Turn Roller Clutch Assembly . . . . . . . . . 3-28
Tray 1 Feed Clutch . . . . . . . . . . . . . . . . 3-29
MPT Pick Up Solenoid . . . . . . . . . . . . . 3-30
Image Processor Isolation. . . . . . . . . . . 3-31
High-Voltage Power Supply (HVPS)
Assembly. . . . . . . . . . . . . . . . . . . . . . . . 3-31
Electrical Noise . . . . . . . . . . . . . . . . . . . 3-33
Exit Sensor . . . . . . . . . . . . . . . . . . . . . . 3-34
Exit Motor . . . . . . . . . . . . . . . . . . . . . . . 3-35
550-Sheet Feeder Feed Clutch . . . . . . . 3-36
Stacker Full Sensor . . . . . . . . . . . . . . . . 3-37
Stacker Offset Operation Not Performed3-38
Envelope Feed Clutch . . . . . . . . . . . . . . 3-38
Envelope No Paper Sensor. . . . . . . . . . 3-39
Phaser 4400 Laser Printer Service Manual