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Service Guide ML320/ML321
Chapter 2 Principles of Operation
2.1
PRINTER OVERVIEW
2.1.01 General Information
This section describes the operation of the printer. It is divided into three parts.
1) Circuit Board Description (
)
The major components of the main controller board are described and functional descriptions
of the operator panel board and power supply are provided. Some signal names are listed with
a (-N) after them. This means that the signal is "active" or ON when it is a logic "0". This is also
indicated by a line over the signal name (I-PRIME).
2) Electrical Operation (
)
This section views the printer functions from an electrical perspective.
3) Mechanical Operation (
)
This section views the printer functions from a mechanical perspective.
Serial Number Identification & (A-D) Revision Levels
A
Rev A units are original production units. An interconnect module connects the power supply board
to the main control board.
B
Rev B units are retrofitted to include a modified interconnect module, which prevents corrosion.
C
Rev C units have a cable harness connection between the power supply board and the main control
board. The cable harness replaces the interconnect module.
D
Rev D units have no power supply board. The circuitry for the power supply board has been
incorporated on the main control board.
Please Note the following:
The Rev C main control board (LXMC) and power supply board (SUII) are downward compatible
with Rev A and B units.
The Rev A and Rev B main control board (LXMC) and power supply board (PAII) cannot be used
in Rev C units.
Rev D units do
NOT
use Rev A, Rev B, or Rev C main control boards, transformers, operator panels,
upper covers, and lower covers. Rev D units have a unique main control board (LXMR), no power supply
board, a 50 volt transformer, and a unique operator panel (LXON).
