Hitachi FS3 Series, Service Manual

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1
8
TROUBLESHOOTING
1.1.5 FAILURE OF POWER SUPPLY TO INDOOR UNIT AND REMOTE CONTROL SWITCH
n
Lights and LCD are not Indicated.
n
Not Operated
If fuses are melted or a breaker is activated, investigate
the cause of over current and take necessary action.
Phenomenon Cause Check Item
Action
(Turn OFF main switch)
Power Failure or Power is Not ON
Measure voltage by
voltmeter
Supply power
Short Circuit Supplied
between Wires
Check for any uncovered
part of wires
Remove the cause of
short circuit and replace
the fuse
Melted Fuse or
Activation of
Breaker at
Power Source
Short Circuit of Wires to Earth
Measure insulation
resistance
Remove the cause of
short-circuit and replace
the fuse
Short Circuit Supplied
between Wires
Check for any uncovered
part of wires
Remove the cause of
short-circuit and replace
the fuse
Melted Fuse at
Control Circuit
Short Circuit of Control Circuit
to Earth
Measure insulation
resistance
Remove the cause of
short-circuit and replace
the fuse
Failure of Transformer at Indoor Unit Side
Measure voltage at
secondary side
Replace the transformer
Disconnected Cable of Remote Control Switch Connect the cable Replace cable or repair It
Insufficient Connection or Incorrect
Connection of Indoor Unit PCB
Insufficient
Contacting at
Connectors of
Remote Control
Switch
Insufficient Connection or Incorrect
Connection of Indoor Unit PCB in
Remote Control Switch
Check connectors Correctly connect It
Failure of Remote Control Switch
Check it by self-checking
mode *1).
Replace remote control
switch if failed
Unconnected Wires to PCB Check connectors Correctly connect wires
Failure of PCB
Failure of PCB
Check it by self-checking
mode *2)
Replace PCB if failed
Incorrect Wiring Connection
Take action according to the procedure indicated in
"TEST RUN".
*1): Refer to Item 1.3.2.
*2): Refer to Item 1.3.1.