Hitachi RAS-25WX8 Manuel De Maintenance page 150

CHECKING THE INDOOR UNIT ELECTRICAL PARTS
1. Power does not come on (no operation)
Is AC220-230V being generated
between terminals A and B on the
indoor unit terminal board?
Is DC35V being generated
between terminals C and D on the
indoor unit terminal board?
Is the control voltage being
generated normally?
12V line: 12V or 7V
5V line: 5V
Do the air deflectors perform initial
operation when the power supply is
turned on after off?
Is the microcomputer reset input (pin )
"Hi"?
Is the microcomputer clock signal
10MHz at pins
generated normally?
Replace the control P.W.B.
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No
Is AC220-230V being generated at
AC outlet?
Yes
No
Is AC220-230V being generated
between terminals A and B on the
outdoor unit terminal board?
Yes
Is DC35V is being generated between
terminals C and D on the outdoor unit
terminal board?
Are C and D connection cables
reversed?
No
Yes
Yes
No
No
Yes
No
and being
Yes
manuals search engine
No
Yes
No
Yes
Yes
No
Yes
No
Perform final operation check.
– 149 –
Check AC outlet and breaker, and
repair any defective part.
Check the power cable, power
switch, and terminal board, and
repair any defective part.
Check the indoor/outdoor unit
connection cable, and correct any
defective section (wrong connection,
incomplete insertion).
Connect the cables correctly.
Check the outdoor unit power circuit,
and repair any defective part.
Check according to the proper method
for checking the power circuit.
Check the wireless light receiving unit.
Check the reset circuit, and repair
any defective section.
Replace the microcomputer and
oscillator.