Xerox Phaser 3155 User Manual

2
Chapter
Theory of Operation
In this chapter...
• Operational Overview
•Paper Path
Downloaded From ManualsPrinter.com Manuals 

2-2Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Operational Overview
The Phaser 3140/3155/3160 is a monochrome printer that has a single-pass laser 
design architecture, which offers mono print speed up to 24 pages per minute 
(ppm), and resolution up to 1200 x 1200 
dots-per-inch (dpi) image quality. The 
printer provides a USB interface for all models, and the 3160N supports 10/100 
Base-TX ethernet.
System Overview
The location of the printer’s primary functional components is...

Phaser 3140/3155/3160 Printer Service Manual2-3
Theory of Operation
Paper Path
The media supplied from the Paper Tray is transported through the printer as 
shown in the illustrations below. Media fed from the manual feed slot enters the 
media path at the Feed Idle Roller.
Paper Feeding
The feeding mechanism consists of the manual feeder, Paper Tray, Pick Up Roller, 
Feed Rollers, and Holder Pad. The rollers and sensors in the paper feed path control 
paper registration and guide the paper through the...

2-4Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Paper Tray
In the Paper Tray, paper is separated by the Holder Pad mounted to the center of 
the tray. Both the side guide and the rear guide can be adjusted for various paper 
sizes. The Paper Empty Sensor detects when the Paper Tray needs to be loaded 
with paper.
Tra y  H o l d e r  Pa d
Individual sheets are separated by the Tray Holder Pad in the Paper Tray. When 
paper feeds into the printer, it passes over the Tray Holder Pad...

Phaser 3140/3155/3160 Printer Service Manual2-5
Theory of Operation
Pick Up Roller
The Pick Up Roller is used to pick up and feed paper into the printer and remove 
static charge on the paper. The Pick Up Roller is driven by the Pick Up Solenoid.
Feed Roller (Registration)
The Feed Roller controls paper registration and guides the paper into the printer.
s3160-090
Pick Up Roller
s3160-089
Downloaded From ManualsPrinter.com Manuals 

2-6Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Drive Assembly
The Drive Assembly receives power from the Controller Board. The Drive Assembly 
consists of the main motor and ge
ar set mounted to a support plate.
• Motor: 24V DC
• Driving Frequency: 2200 rpm
s3160-084
3155 & 3160 3140
Downloaded From ManualsPrinter.com Manuals 

Phaser 3140/3155/3160 Printer Service Manual2-7
Theory of Operation
Laser Unit
The Laser Unit is the core part of the Phaser 3140/3155/3160 and is controlled by 
the video controller circuitry of the Controller Board. The Laser Unit converts video 
data received from the Controller Board into an electrostatic latent image on the 
surface of the OPC drum. This is achieved by controlling the laser beam and 
exposing the surface of the OPC drum to the laser light. A rotating polygon mirror 
reflects the...

2-8Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Print Cartridge
The Print Cartridge is an integral unit containing the OPC unit and toner unit. The 
OPC unit consists of the OPC drum and charging roller. The toner unit consists of 
toner, supply roller, developing roller, and cleaning blade.
• Developing method: Non-magnetic 1 element contacting method
• Toner: non-magnetic 1 element shatter type toner
• Toner Life: 1,000 pages/2,500 pages (ISO 19752 Pattern/A4 Standard)
• Toner...

Phaser 3140/3155/3160 Printer Service Manual2-9
Theory of Operation
Fuser
The Fuser consists of a Halogen Lamp, Heat Roller, Pressure Roller, Thermistor, and 
Thermostat. The Heat Roller transfers he
at from the lamp to the paper. The 
Pressure Roller adheres the melted toner to the media surface. The Thermistor and 
Thermostat monitor Fuser operating temperature.
Halogen Lamp
•Voltage
• 120V: 115 V ± 5%
• 220V: 230 V ± 5%
• Capacity: 750 Watt ± 25 W
Thermistor
The Thermistor detects the temperature of...

2-10Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Pressure Roller
The Pressure Roller is made of a silicon resin and the surface is coated with Teflon. 
When media passes between the Heat Roller and the Pressure Roller, toner is 
melted and permanently fixed to the surface of the paper.
Safety Features
Several protection devices are used to prevent Fuser overheating:
• Hardware cuts off Fuser power when overheating is detected.
• Software cuts off Fuser power when overheating is...