Mitsubishi FDT71VH User Manual

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51
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'20 • PAC-SM-351
1.2 MAINTENANCE DATA
1.2.1 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 unit control PCB Outdoor unit control PCB
Location of trou-
ble
Description of trouble Repair method
Reference
page
Error code Red LED Red LED
Green
LED (1)
Red LED
Green
LED (1)
No-indication Stays OFF
Stays OFF
Keeps
flashing
Stays OFF
Keeps
flashing
—
• Normal operation
—
—
Stays OFF Stays OFF 2-time flash Stays OFF Indoor unit power source • Power OFF, broken wire/blown fuse, broken transformer wire Repair 88
*
3-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Remote control wires • Poor connection, breakage of remote control wire * For wire breaking at power ON, the LED is OFF. Repair
89
Remote control • Defective remote control PCB
Replacement of
remote control
WAIT
or
INSPECT I/U
Stays OFF
Keeps
flashing
2-time
flash
Keeps
flashing
Indoor-outdoor units
connection wire
• Poor connection, breakage of indoor-outdoor units connection wire
Repair
90-94
Remote control • Improper setting of master and slave by remote control
Keeps
flashing
Stays OFF
*
Keeps
flashing
Stays OFF
Keeps
flashing
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
96
Remote control
indoor unit control
PCB
*• Defective remote control or indoor unit control PCB (defective communication circuit)?
Replacement of remote
control or PCB
2-time
flash
Keeps
flashing
2-time
flash
Keeps
flashing
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
97
2-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
(Noise) • CPU-runaway on outdoor unit control PCB
Power reset or
Repair
Outdoor unit control
PCB
*• Occurrence of defective outdoor unit control PCB on the way of power source (defective
communication circuit)?
Replacement of
PCB
2-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Outdoor unit control
PCB
• Defective outdoor unit control PCB on the way of power source
Replacement
Fuse • Blown fuse
1-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Indoor heat
exchanger tempera
-
ture sensor
• Defective indoor heat exchanger temperature sensor (defective element, broken
wire, short-circuit)
• Poor contact of temperature sensor connector
Replacement, repair
of temperature sen-
sor
98
Indoor unit control PCB
*• Defective indoor unit control PCB (Defective temperature sensor input circuit)?
Replacement of PCB
1-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Indoor return air
temperature sensor
• Defective indoor return air temperature sensor (defective element, broken wire,
short-circuit)
• Poor contact of temperature sensor connector
Replacement, repair
of temperature sen
-
sor
99
Indoor unit control PCB
*• Defective indoor unit control PCB (Defective temperature sensor input circuit)?
Replacement of PCB
1-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Installation or oper
-
ating condition
• Heating over-load (Anomalously high indoor heat exchanger temperature) Repair
100
Indoor heat
exchanger tempera
-
ture sensor
• Defective indoor heat exchanger temperature sensor (short-circuit)
Replacement of
temperature sensor
Indoor unit control PCB
*• Defective indoor unit control PCB (Defective temperature sensor input circuit)?
Replacement of PCB
1-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Drain trouble • Defective drain pump (DM), broken drain pump wire, disconnected connector
Replacement, repair
of DM
101
Float switch • Anomalous float switch operation (malfunction) Repair
Indoor unit control PCB
*• Defective indoor unit control PCB (Defective float switch input circuit)
*• Defective indoor unit control PCB (Defective DM drive output circuit)?
Replacement of
PCB
Option • Defective option parts (At option anomalous input setting) Repair
Stays OFF
Keeps
flashing
Stays OFF
Keeps
flashing
Number of connect
-
ed indoor units
• When multi-unit control by remote control is performed, the number of units
is over
Repair
102
Stays OFF
Keeps
flshing
Stays OFF
Keeps
flshing
Address setting
error
• Address setting error of indoor units Repair
103
3-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Indoor unit No. setting •No master is assigned to slaves.
Repair
104
Rcmote control wires •Anomalous remote control wire connection, broken wire between master and slave units
1(2)-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Indoor fan motor • Defective indoor fan motor Replacement, repair
105
Indoor unit power PCB • Defective indoor unit power PCB Replacement
1-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Address
setting error
• Address setting error of master and slave indoor units Repair
106
1-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Indoor unit control PCB • Indoor unit operation check error Repair 107
1(2)-time
flash
Keeps
flashing
Stays OFF
Keeps
flashing
Indoor fan motor • Indoor motor rotation speed anomaly Replacement, repair
108
Indoor unit power PCB • Defective indoor unit power PCB Replacement
Stays OFF
Keeps
flashing
Stays OFF
Keeps
flashing
Remote control
temperature sensor
• Broken wire of remote control temperature sensor Repair 109
Notes (1)
Normal indicator lamp (Indoor, outdoor units: Green) extinguishes (or lights continuously) only when CPU is anomalous. It
keeps ashing in any trouble other than anomalous CPU.
(2) *markinthedescriptionoftroublemeansthat,inordinarydiagnosis,itcannotidentifythecausedenitely,and,ifthetroubleisrepairedbyreplacing
the part, it is judged consequently that the replaced part was defective.
1) FDT, FDTC, FDU, FDUM, FDE series

Mitsubishi FDT71VH Specifications

General

Brand	Mitsubishi
Model	FDT71VH
Category	Air Conditioner
Language	English