Hitachi Utopia RPI-2.5HRG Service Manual page 28

Alarm
Code
G "RUN" light flickers and "ALARM" is indicated on the remote control switch.
G The unit No., alarm code and the unit code is alternately indicated on the set temperature section,
and the alarm code is indicated on the display of the outdoor unit PCB1.
# This alarm is indicated when abnormality is maintained for 30 seconds after normal transmitting
between the outdoor unit PCB1 and ISPM, and also abnormality is maintained for 30 seconds after
the micro-computer is automatically reset. The alarm is indicated when the abnormal transmitting is
maintained for 30 seconds from starting of the outdoor unit.
Disconnect CN6 of PCB1
Is LED2 (Green) on PCB1
flickering?
Connect CN6 of PCB1
Is LED2 (Green) on PCB1
flickering?
Does flickering speed become
faster than before?
Normal ISPM
check the wiring again.
Abnormal Transmitting between Inverter and Outdoor PCB1
No
Yes
No
Yes
No
Yes
TROUBLESHOOTING
Faulty PCB1.
Faulty ISPM.
Incorrect wiring between ISPM
and PCB1.
Faulty PCB1.
Faulty ISPM.
Disconnected wires or Insufficient
Contacting between ISPM and
PCB1.
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