Canon iR1200 Series Service Manual page 5

The descriptions in this Service Manual are based on he following rules:
1. In each chapter, the uses of the function in question and its relationship to electrical and
mechanical systems are discussed and the timing of operation of its associated parts is
explained by means of outlines and diagrams.
In the diagrams, the symbol
with a name next to it indicates the flow of an electric signal.
The expression "turn on the power" means turning on the power switch, closing the
front cover, and closing the delivery cover so that the machine will be supplied with
power.
2. In circuit diagrams (digital), a signal whose level is High is expressed as being '1',
while a single whose level is Low is expressed as being '0'; the level of voltage, how-
ever, varies from circuit to circuit.
The machine uses CPUs, whose internal mechanisms cannot be checked in the field,
and, therefore, are not explained. In addition, the machine's PCBs are not intended for
repairs at the user's and, therefore, are explained by means of block diagrams: two types
are used, i.e., between sensors and inputs of PCBs equipped with a control or drive func-
tion and between outputs equipped with a control or drive function and loads; in addi-
tion, functional block diagrams are used at times.
Changes made to the machine for product improvement are communicated in the form of
a Service Information bulletin as needed. All service persons are expected to go through all
service documentation including the bulletins and be equipped to respond to the needs of the
field (as by being able to identify possible causes of problems).
COPYRIGHT © 2002 CANON INC.
represents a mechanical path, while the symbol
2000 2000 2000 2000 CANON iR1200/iR1300 Series REV. 0 AUG. 2002
INTRODUCTION
iii