Canon iR2020 Series Installation Procedure page 5

Introduction
The following rules apply throughout this Service Manual:
1. Each chapter contains sections explaining the purpose of specific functions and the rela-
tionship between electrical and mechanical systems with reference to the timing of operation.
In the diagrams,
panies the symbol , the arrow
The expression "turn on the power" means flipping on the power switch, closing the front
door, and closing the delivery unit door, which results in supplying the machine with power.
2. In the digital circuits, '1'is used to indicate that the voltage level of a given signal
is "High", while '0' is used to indicate "Low".(The voltage value, however, differs from
circuit to circuit.) In addition, the asterisk (*) as in "DRMD*" indicates that the DRMD
signal goes on when '0'.
In practically all cases, the internal mechanisms of a microprocessor cannot be checked in
the field. Therefore, the operations of the microprocessors used in the machines are not
discussed: they are explained in terms of from sensors to the input of the DC controller PCB
and from the output of the DC controller PCB to the loads.
The descriptions in this Service Manual are subject to change without notice for product im-
provement or other purposes, and major changes will be communicated in the form of Service
Information bulletins.
All service persons are expected to have a good understanding of the contents of this Service
Manual and all relevant Service Information bulletins and be able to identify and isolate
faults in the machine."
represents the path of mechanical drive; where a signal name accom-
indicates the direction of the electric signal.