Hitachi FSXN Series Service Manual page 186

8 Troubleshooting
04
Alarm code
• The RUN indicator flashes and the ALARM indication is displayed on the remote control switch.
• The unit no., the alarm code and the unit code are alternatively displayed in the temperature setting section and the unit
no. and alarm code are displayed on the outdoor unit's PCB1 display.
* This alarm is indicated when an anomaly is maintained for 30 seconds after the normal transmission between PCB1
and PCB2 of the outdoor unit, and also if the anomaly is maintained for 30 seconds after the microcomputer is
automatically reset. The alarm is indicated when abnormal transmission is maintained for 30 seconds after the outdoor
unit is turned on.
No
Is LED2 (green) on
PCB1 flashing?
Yes
Check the wiring
between PCB1 and
PCB2.
Check PCB2.
Phenomenon
Between PCB1 and
Disconnected
PCB2
Wires, Insufficient
Contacting or
Incorrect
Power Source Wiring
Connection
for Outdoor Unit
Faulty PCB
PCB1 and PCB2
Faulty Electrical
Components
Power Fuse,
Disconnected
Resistance
Incoming Current Limit
Resistance
Disconnected Wires
Insufficient Contacting
Incorrect Wiring
*1): When the unit is applied the excessive surge current due to lightning or other causes, alarm code "04" or Inverter
stoppage code (IT) "11" is indicated and the unit cannot be operated. In this case, check to ensure the surge absorver
(SA) in the noise filter (NF1, NF2). The surge absorver may be damaged if the inner surface of the SA is black. If so, replace
surge absorver.
If the inside of the surge absorver is normal, turn OFF the power supply and wait for LED201 (red) of PCB2 OFF
(approximately 5 minutes) and turn ON power supply again.
180
SMGB0065 rev. 1 - 12/2010
Abnormal transmission between the inverter PCB and the outdoor unit PCB.
Disconnect CN14
of PCB1.
Is LED2 (green) on
PCB1 flashing?
No
Faulty PCB1.
Cause
Disconnected Wires
to PCB
Faulty PCB
Melted Power Fuse
Incorrect Wiring
PCB1: Control PCB in Outdoor Unit
PCB2: Inverter PCB
Yes
Check PCB2. *1)
<Outdoor Unit PCB1 Display Indication>
Abnormal Transmitting
of Inverter
Check Item
Check continuity of
wires.
Check for looseness
of connection screws.
Check connection No.
Check connections.
Check conductivity
of power fuse, power
transistor, diode module.
Check resistance of
incoming current limit
resistance.
Check continuity.
Check for looseness
of connection screws.
Check connection Nos.
Action
(Turn OFF Main Switch)
Replacing wires,
repairing, tightening
screws and incorrect
wiring.
Repair wiring
connections.
Replace PCB if faulty.
Replace power fuse,
power transistor, and
diode module.
Replace incoming
current limit resistance.
Replacing Wires,
Repairing and
Tightening Screws
Correctly Connect
Wires