Hitachi Summit RAC-18YH5, Service Manual

Page: 79 / 96

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Is
220-230V
being
generated
Are
the
connections
for
terminals
C
and
D
correct?
Is
5V
being
generated
between
Pin
4
(0V)and
Pin
3
(5V)at
CN
Is
the
15A
fuse
normal?
[No
operation
or
abnormal
operation]
Be
sure
to
turn
the
power
of
f
before
correcting
the
connection.
mainly
,varistor
(VS2),
3A
fuse,
smoothing
capacitors,
IPM,
etc.
The
SW
power
supply
s
overcurrent
protection
is
activated,
disabling
the
microcomputer
.
Correct
properly
.
If
the
15A
fuse
has
blown,
be
aware
that
other
parts
may
also
be
defective.
Replace
defective
parts.
Is
the
power
circuit
normal?
See
the
description
on
power
circuit
for
details
.
Is
the
switching
power
circuit
OK?
Has
the
3A
fuse
blown?
Check
to
see
if
C
and
D
cables
are
connected
correctly
.
If
reversed
or
incompletely
inserted,
correct
the
cable
connection.
Replace
any
defective
parts.
If
the
3A
fuse
has
blown,
the
varistor
2,
etc.
may
also
be
defective.
With
the
piping
and
lines
(A,
B,
C,
D)connected,
operate
the
unit
in
the
forced
cooling
mode
using
the
outdoor
unit
service
switch.
How
did
the
self-diagnosis
lamp
(LD301)blink?
See
the
self-diagnosis
lamp
mode.
Ye
s
Ye
s
Power
is
OK
Ye
s
Ye
s
Ye
s
No No No No
NG
(Fuse
blown)
18
(test
pin)?
at
terminals
A
and
B?