Hitachi RAS-25CNH1 Service Manual page 89

Is AC 220V voltage being generated
between terminals A and B of the terminal
board?
YES
Is a DC 35V voltage generated between
terminals C and D of the terminal board?
YES
Is the air conditioner operated by pressing
the temporary operation switch?
NO
Does the timer lamp blink 13 times when
the breaker is turned ON?
NO
Is the control voltage generated normally?
YES
Is micro computer reset input (pin
to Hi ?
YES
Does micro computer clock (pins
oscillate normally?
YES
Replace the control P.W.B..
NO
Is AC 220V voltage being generated at
power outlet?
NO
Is a AC 220V voltage generated between
terminals A and B of the terminal board
in the outdoor unit?
Is a DC 35V voltage generated between
terminals C and D of the terminal board
in the outdoor unit?
Are jumper cables C and D connected in
reverse?
YES
Check the remote controller. (Refer to
Checking the remote controller .)
Is there poor contact of CN2, disconnec-
tion of leads, etc.?
YES
NO
Is DC 12V voltage being generated at
both ends of C102?
Is a DC 12V voltage generated between
and of REG2?
G
I
) set
17
Is a DC 5V voltage generated between
o and of REG2?
G
NO
, )
15 16
NO
Perform a final check of operation.
NO
YES
NO
YES
YES
NO
YES
NO
NG
OK
NG
OK
NO
YES
NO
YES
NO
– 98 –
Check power outlet and breaker and
repair defective parts.
YES
Check power cord, power switch and
terminal board. Repair defective parts.
Check the indoor/outdoor connection
cable and correct the abnormal state
(wrong connection, poor insertion, etc.).
Correct the connection.
Check the power circuit and peripherals
and correct the defective parts.
Replace the remote controller.
Correct the lead wires, connection of the
connector.
Replace the light receiving unit.
Replace IC401.
Check that there is no abnormality such
as a pattern short on the P.W.B., heating
of parts, etc. and replace REG1.
(If the output is 15V or more, it is also
abnormal. Replace it.)
Check that there is no abnormality such
as a pattern short on the P.W.B., heating
of parts, etc. and replace REG2.
Check the reset circuit and repair
defective parts.
Replace the micro computer and
oscillator.