-
224
-
'17 • SCM-T-225
8.2
FDTC, FDEN, FDE and FDUM series
8.2.1
Diagnosing of microcomputer circuit
(1) Selfdiagnosis function
(a) Check indicator table
Whether a failure exists or not on the indoor unit and outdoor unit can be know by the contents of remote control error code,
indoor/outdoor unit green LED (power pilot lamp and microcomputer normality pilot lamp) or red LED (check pilot lamp).
(i) Indoor unit
Remote control
Indoor control PCB Outdoor
main PCB
Location of trouble
Description of trouble
Repair method Reference
page
Error code Red LED Red LED
Green
LED (1) Red LED
No-indication Stays OFF
Stays OFF
Keeps
flashing Stays OFF
—
• Normal operation
—
—
Stays OFF Stays OFF Stays OFF
Indoor unit power source
• Power OFF, broken wire/blown fuse, broken transformer wire
Repair
247
*
3-time
flash
Keeps
flashing Stays OFF
Remote control wires
• Poor connection, breakage of remote control wire * For wire breaking at power ON, the LED is OFF.
Repair
248
Remote control
• Defective remote control PCB
Replacement of
remote control
WAIT
or
INSPECT I/U
Stays OFF
Keeps
flashing Stays OFF
Indoor-outdoor units connection
wire
• Poor connection, breakage of indoor-outdoor units connection wire
Repair
249−253
Remote control
• Improper setting of master and slave by remote control
Keeps
flashing
Stays OFF
*
Keeps
flashing Stays OFF
Remote control wires (Noise)
•
Poor connection of remote control signal wire (White)
•
Intrusion of noise in remote control wire
* For wire breaking at power ON, the LED is OFF
Repair
254
Remote control indoor control
PCB
*
• Defective remote control or indoor control PCB (defective communication circuit)?
Replacement of
remote control or
PCB
2-time
flash
Keeps
flashing
6-time
flash
Indoor-outdoor units connection
wire
•
Poor connection of wire between indoor-outdoor units during operation
(disconnection, loose connection)
•
Anomalous communication between indoor-outdoor units by noise, etc.
Repair
255
2-time
flash
Keeps
flashing
6-time
flash
(Noise)
•
CPU-runaway on outdoor control PCB
Power reset or
Repair
Outdoor control PCB
*
• Occurrence of defective outdoor control PCB on the way of power source (defective communication
circuit)?
Replacement of
PCB
2-time
flash
Keeps
flashing
6-time
flash
Outdoor control PCB
•
Defective outdoor control PCB on the way of power source
Replacement
Fuse
•
Blown fuse
1-time
flash
Keeps
flashing Stays OFF
Indoor heat exchanger tempera-
ture thermistor
•
Defective indoor heat exchanger temperature thermistor
(defective element, broken wire,
short-circuit)
• Poor contact of temperature thermistor connector
Replacement,
repair of tempera-
ture thermistor
256
Indoor control PCB
*
•
Defective indoor control PCB (Defective temperature thermistor input circuit)?
Replacement of
PCB
1-time
flash
Keeps
flashing Stays OFF
Indoor return air temperature
thermistor
•
Defective indoor return air temperature thermistor
(defective element, broken wire, short-
circuit)
• Poor contact of temperature thermistor connector
Replacement,
repair of tempera-
ture thermistor
257
Indoor control PCB
*
•
Defective indoor control PCB (Defective temperature thermistor input circuit)?
Replacement of
PCB
1-time
flash
Keeps
flashing Stays OFF
Installation or operating condi-
tion
•
Heating over-load
(Anomalously high indoor heat exchanger temperature)
Repair
258
Indoor heat exchanger tempera-
ture thermistor
•
Defective indoor heat exchanger temperature thermistor (short-circuit)
Replacement
of temperature
thermistor
Indoor control PCB
*
•
Defective indoor control PCB
(Defective temperature thermistor input circuit)?
Replacement of
PCB
1-time
flash
Keeps
flashing Stays OFF
Drain trouble
•
Defective drain pump (DM), broken drain pump wire
, disconnected connector
Replacement,
repair of DM
259
Float switch
•
Anomalous float switch operation
(malfunction)
Repair
Indoor control PCB
*
•
Defective indoor control PCB
(Defective float switch input circuit)
*
•
Defective indoor control PCB
(Defective DM drive output circuit)?
Replacement of
PCB
Option
•
Defective option parts
(At optional anomalous input setting)
Repair
Stays OFF
Keeps
flashing Stays OFF
Number of connected indoor
units
•
When multi-unit control by remote control is performed, the number of units is over
Repair
260
Keeps
flashing
Keeps
flashing Stays OFF
Address
setting error
•
Address setting error of indoor units
Repair
261
1-time
flash
Keeps
flashing Stays OFF
Fan motor
•
Defective fan motor
Replacement,
repair
262
Indoor control PCB
•
Defective indoor control PCB
Replacement
1-time
flash
Keeps
flashing Stays OFF
Indoor control PCB
•
Improper operation mode setting
Repair
263
1-time
flash
Keeps
flashing Stays OFF
Fan motor
• Indoor fan motor rotation speed anomaly
Replacement, repair
264
Indoor power PCB
• Defective indoor power PCB
Replacement
Stays OFF
Keeps
flashing Stays OFF
Remote control temperature
thermistor
• Broken wire of remote control temperature thermistor
Repair
265
Note (1)
Normal indicator lamp (Indoor unit: Green) extinguishes (or lights continuously) only when CPU is anomalous. It keeps flashing
in any trouble other than anomalous CPU.
(2) * 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.
(In case of FDTC, FDUM)
(In case of FDTC, FDUM)
(In case of FDTC, FDUM)
