Maintenance Data; Diagnosing Of Microcomputer Circuit; Self-Diagnosis Function - Mitsubishi Heavy Industries FDTC40ZSXVH Service Manual

2. MAINTENANCE DATA

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
Error code Red LED Red LED
Stays OFF
Stays OFF Stays OFF
No-indication Stays OFF
*
3-time
flash
or
WAIT
Stays OFF
INSPECT I/U
Stays OFF
2-time
flash
2-time
flash
2-time
flash
1-time
flash
1-time
flash
Keeps
flashing
1-time
flash
1-time
flash
Stays OFF
Keeps
flashing
1(2)-time
flash
1-time
flash
1(2)-time
flash
Stays OFF
Note (1) Normal indicator lamp (Indoor, outdoor units: 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.
Outdoor control PCB
Location of trou-
Green Green
ble
Red LED
LED (1) LED (1)
Keeps Keeps
Stays OFF —
flashing flashing
2-time Indoor unit power
Stays OFF
flash source
Remote control
wires
Keeps Keeps
Stays OFF
flashing flashing
Remote control
Indoor-outdoor
units connection
Keeps 2-time Keeps
wire
flashing flash flashing
Remote control
Remote control
*
wires (Noise)
Keeps Keeps
Stays OFF
flashing flashing
Remote control
indoor control PCB
Indoor-outdoor
Keeps 2-time Keeps
units connection
flashing flash flashing
wire
(Noise)
Keeps Keeps
Stays OFF
flashing flashing
Outdoor control
PCB
Outdoor control
Keeps
PCB
Stays OFF Stays OFF
flashing
Fuse
Indoor heat
exchanger tempera-
Keeps Keeps
ture sensor
Stays OFF
flashing flashing
Indoor control PCB
Indoor return air
temperature sensor
Keeps Keeps
Stays OFF
flashing flashing
Indoor control PCB
Installation or oper-
ating condition
Indoor heat
Keeps Keeps
Stays OFF exchanger tempera-
flashing flashing
ture sensor
Indoor control PCB
Drain trouble
Float switch
Keeps Keeps
Stays OFF
flashing flashing
Indoor control PCB
Option
Keeps Keeps Number of connect-
Stays OFF
flashing flashing ed indoor units
Keeps Keeps Address
Stays OFF
flashing flashing setting error
Fan motor
Keeps Keeps
Stays OFF
flashing flashing
Indoor power PCB • Defective indoor power PCB
Keeps Keeps
Stays OFF Indoor control PCB • Improper operation mode setting
flashing flashing
Fan motor
Keeps Keeps
Stays OFF
flashing flashing
Indoor power PCB • Defective indoor power PCB
Keeps Keeps Remote control
Stays OFF
flashing flashing temperature sensor
Description of trouble
• Normal operation
• Power OFF, broken wire/blown fuse, broken transformer wire
• Poor connection, breakage of remote control wire * For wire breaking at power ON, the
LED is OFF.
• Defective remote control PCB
• Poor connection, breakage of indoor-outdoor units connection wire
• Improper setting of master and slave by remote control
• Poor connection of remote control signal wire (White)
• Intrusion of noise in remote control wire
*
• Defective remote control or indoor control PCB (defective communication circuit)?
• Poor connection of wire between indoor-outdoor units during operation
(disconnection, loose connection)
• Anomalous communication between indoor-outdoor units by noise, etc.
• CPU-runaway on outdoor control PCB
*
• Occurrence of defective outdoor control PCB on the way of power source (defective com-
munication circuit)?
• Defective outdoor control PCB on the way of power source
• Blown fuse
• Defective indoor heat exchanger temperature sensor (defective element, broken
wire, short-circuit)
• Poor contact of temperature sensor connector
*
• Defective indoor control PCB (Defective temperature sensor input
circuit)?
• Defective indoor return air temperature sensor (defective element, broken wire,
short-circuit)
• Poor contact of temperature sensor connector
*
• Defective indoor control PCB (Defective temperature sensor input
circuit)?
• Heating over-load (Anomalously high indoor heat exchanger temperature)
• Defective indoor heat exchanger temperature sensor (short-circuit)
*
• Defective indoor control PCB (Defective temperature sensor input circuit)?
• Defective drain pump (DM), broken drain pump wire, disconnected connector
• Anomalous float switch operation (malfunction)
*
• Defective indoor control PCB (Defective float switch input circuit)
*
• Defective indoor control PCB (Defective DM drive output circuit)?
• Defective option parts (At option anomalous input setting)
• When multi-unit control by remote control is performed, the number of units
is over
• Address setting error of indoor units
• Defective fan motor
• Indoor fan motor rotation speed anomaly
• Broken wire of remote control temperature sensor
32
- -
'18 • PAC-SM-297
Repair method
Replacement of
remote control
* For wire breaking at power ON, the LED is OFF
Replacement of
remote control or
Power reset or
Replacement of
Replacement
Replacement, repair
of temperature
Replacement of
Replacement, repair
of temperature
Replacement of
Replacement of
temperature sensor
Replacement of
Replacement, repair
Replacement of
Replacement, repair
Replacement
Replacement, repair
Replacement
Reference
page
— —
Repair 54
Repair
55
Repair 56-60
Repair
62
PCB
Repair
Repair
63
PCB
sensor
64
PCB
sensor
65
PCB
Repair
66
PCB
of DM
Repair
67
PCB
Repair
Repair 68
Repair 69
70
Repair 71
72
Repair 73