Canon USB Application Interface Board-D1, Service Manual

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Introduction
The following rules apply throughout this Service Manual:
1. Each chapter contains sections explaining the purpose of specific functions and the
relationship between electrical and mechanical systems with reference to the timing of
operation.
In the diagrams, represents the path of mechanical drive; where a signal name
accompanies the symbol, the arrow indicates the direction of the electric
signal.
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
improvement 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."