Mitsubishi Heavy Industries FDTC40ZHXV Technical Manual page 265

(ii) Outdoor unit side
1) Model SRC40~60
Indoor unit control
Remote controller
PCB
Error
Red LED Red LED Green LED Red LED
code
Stays OFF
flashing
Stays OFF
flashing
Stays OFF
flashing
Stays OFF
flashing
Stays OFF
Keeps
flashing
flashing
Stays OFF
flashing
Stays OFF
flashing
Stays OFF
flashing
Stays OFF
flashing
Stays OFF
flashing
Stays OFF
flashing
Stays OFF
flashing
Note (1) * mark in the Description of trouble means that, in ordinary diagnosis, it cannot identify the cause definitely, and, if the trouble is repaired by replacing the
part, it is judged consequently that the replaced part was defective.
Outdoor unit
control PCB Location of
trouble
Keeps
1 time flash Power supply wires • Anomalous current on inverter primary side
Installation,
operation status
Outdoor unit
Keeps heat exchanger
8 times flash
temperature
thermistor
Outdoor unit
control PCB
Installation,
operation status
Discharge pipe
Keeps
8 times flash temperature
thermistor
Outdoor unit
control PCB
Outdoor unit
heat exchanger
Keeps temperature
8 times flash
thermistor
Outdoor unit
control PCB
Ambient air
temperature
Keeps
8 times flash thermistor
Outdoor unit
control PCB
Discharge pipe
temperature
Keeps
8 times flash thermistor
Outdoor unit
control PCB
Outdoor unit
control PCB
Keeps
1 time flash compressor
Installation,
operation status
Outdoor unit
Keeps
1 time flash control PCB power
transistor
DC fan motor
Keeps Keeps
Outdoor unit
flashing
control PCB
Operation status
Keeps
2 times flash
Installation status • Service valve closing operation
Compressor
Keeps
2 times flash outdoor unit control
PCB
Keeps
7 times flash Compressor
Description of trouble
• Higher outdoor unit heat exchanger temperature
• Defective outdoor unit heat exchanger temperature thermistor
*• Defective outdoor unit control PCB (Defective temperature sensor
input circuit)?
• Higher discharge temperature
• Defective discharge pipe temperature thermistor
*• Defective outdoor unit control PCB (Defective temperature sensor
input circuit)?
• Defective outdoor unit heat exchanger temperature thermistor,
broken wire or poor connector connection
*• Defective outdoor unit control PCB (Defective temperature sensor
input circuit)?
• Defective ambient air temperature thermistor, broken wire or poor
connector connection
*• Defective outdoor unit control PCB (Defective temperature sensor
input circuit)?
• Defective discharge pipe temperature thermistor, broken wire or
poor connector connection
*• Defective outdoor unit control PCB (Defective temperature sensor
input circuit)?
• Current cut (Anomalous compressor over-current)
• Service valve closing operation
• Anomalous inverter over-voltage
• Defective DC fan motor
• Defective outdoor unit control PCB
• Shortage in refrigerant quantity
• Anomalous compressor startup
• Anomalous compressor rotor lock
248
– –
Reference
Repair method
page
Repair 296
Repair
Replacement,
repair of
299
temperature
thermistor
Replacement of
PCB
Repair
Replacement,
repair of
301
temperature
thermistor
Replacement of
PCB
Replacement,
repair of
temperature
302
thermistor
Replacement of
PCB
Replacement,
repair of
temperature
303
thermistor
Replacement of
PCB
Replacement,
repair of
temperature
304
thermistor
Replacement of
PCB
Replacement of
PCB
307, 308
Repair
Repair
310
PCB replacement
Replacement 311
Repair
319
Service valve
opening check
Replacement 320
Replacement 322