Gp 5.18 Electrical - Xerox DocuPrint N2025 Service Manual

Figure 2 Laser Scanning
Initial Issue
DocuPrint N2025/N2825

GP 5.18 Electrical

Interlock Switch – Figure 1
A safety switch that interrupts the supply of 24 VDC from the LVPS to the Print Engine Control-
ler PWB when the Top Cover is open. This switch also causes the LVPS to interrupt AC line
voltage to the Fuser Assembly.
Fuser Interlock Switch –
A safety switch for stopping the operation of the Motor:Main, the Laser, and the Fuser Assem-
bly when the Exit Assembly is open.
Fuser Fan and LVPS Fan –
Exhausts the air inside the printer and introduces fresh air to prevent an excessive rise of the
inside temperature.
LVPS Assembly –
Produces regulated low DC voltages (5V supplied to logic circuits, 5V-LD supplied to the Laser
Diode, and 24V supplied to motors, solenoids, and clutches) from AC power. It also switches
on and off the AC power to the Heater Rod of the Fuser Assembly.
The LVPS Assembly contains the Fan control circuit, the Heater Rod switching circuit, and has
Main Power Switch connected to it.
HVPS Assembly –
Produces high AC and DC voltages applied to charge (BCR), development (Magnet Roll),
transfer (BTR), and detack (Detack Saw).
Print Engine Controller PWB –
The Print Engine Controller PWB (Main Control Unit) controls all printer operations responding
to signals from the Control Panel, Controller, and sensors and switches. The Print Engine Con-
troller PWB has the following six major functions.
1. Communicates with the Controller.
2. Communicates with the optional Duplex Assembly.
3. Receives information from the printer sensors and switches.
4. Controls the Laser, Fuser, and Motor:Main.
5. Controls the printing process.
6. Distributes DC power from the LVPS Assembly to other printer components.
The Print Engine Controller PWB consists of a single chip, 8-bit microcomputer and ASICs
(Application Specific Integrated Circuit for image data transfer and communication control. The
microcomputer has ROM, RAM, 16-bit integrated timer unit, programmable timing pattern con-
troller, watch dog timer, serial communication interfaces, and A/D converter, a D/A converter, I/
O ports, DMA controller, and refresh controller built in.
02/2000
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General Procedures / Information
GP 5.17, GP 5.18