Maintenance Data; Diagnosing Of Microcomputer Circuit; Selfdiagnosis Function - Mitsubishi Heavy Industries SRK100VNXPZSX Technical Manual

1.10 MAINTENANCE DATA

1.10.1 Diagnosing of microcomputer circuit

(1) Selfdiagnosis function

Check Indicator Table
At the indoor unit side, errors are displayed with the combination of RUN light and TIMER light on the display panel.
(i) Indoor unit
SRK series
Remote control Indoor unit display
Error code Red LED RUN light TIMER light Red LED Green LED
ON
—
No-indication Stays OFF
—
Stays OFF
or
WAIT
—
INSPECT I/U
—
ON
ON
ON
1-time flash
Keeps
flashing
3-time
flash
2-time
No-indication
flash
—
—
6-time
flash
—
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 control PCB
Location of
trouble
Keeps
Stays OFF Stays OFF —
flashing
2-time Indoor unit power
— Stays OFF
flash source
Remote control
wires
Keeps
—
Stays OFF
flashing
Remote control
Limit switch,
Keeps Keeps air inlet panel
Stays OFF
flashing flashing
Indoor control PCB •Defective indoor control PCB (Defective limit switch input circuit)?
Indoor-outdoor
units connection
2-time Keeps
—
wire
flash flashing
Remote control
Remote control
wires (Noise)
Keeps
Stays OFF
—
flashing
Remote control
indoor control PCB
Indoor-outdoor
6 -time 2 -time Keeps
units connection
flash flash flashing
wire
(Noise)
6 -time Keeps
Stays OFF
flash flashing
Outdoor control
PCB
Outdoor control
6 -time
PCB
Stays OFF Stays OFF
flash
Fuse
Indoor heat
exchanger tempera
Keeps
ture sensor 1
ON Stays OFF
flashing
Indoor control PCB •Defective indoor control PCB (Defective temperature sensor 1 input
Indoor heat
exchanger tempera
Keeps
ture sensor 2
ON Stays OFF
flashing
Indoor control PCB
Indoor room
temperature sensor
Keeps
ON Stays OFF
flashing
Indoor control PCB
Keeps Number of con-
— Stays OFF
flashing nected indoor units
Indoor unit No. set-
Keeps
ting
Stays OFF
—
flashing
Rcmote control wires •Anomalous remote control wire connection, broken wire between master and slave units
Fan motor
Keeps
ON Stays OFF
flashing
Indoor control PCB •Defective indoor control PCB
Remote control
Keeps
— Stays OFF
temperature thermistor
flashing
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
•Limit switch operate
•Defective limit switch (Poor contact of limit switch connector)
•Set is defective air inlet panel
• 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 circ uit)?
•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 1 (defective element, broken
wire, short-circuit)
• Poor contact of temperature sensor 1 connector
circuit)?
• Defective indoor heat exchanger temperature sensor 2
wire, short-circuit)
• Poor contact of temperature sensor 2 connector
• Defective indoor control PCB (Defective temperature sensor 2 input
circuit)?
• Defective indoor room temperature sensor (defective element, broken wire,
short-circuit)
• Poor contact of temperature sensor connector
• Defective indoor control PCB (Defective temperatuer sensor input circuit)?
※
•When multi-unit control by remote control is performed, the number of
units is over
•No master is assigned to slaves.
•Defective fan motor
• Broken wire of remote control temperature thermistor
84
- -
'17 • PAC-T-257
Repair method
—
Repair
Repair
Replacement of
remote control
Replacement, repair
Replacement of
PCB
Repair
Repair
* For wire breaking at power ON, the LED is OFF
Replacement of
remote control or
PCB
Repair
Power reset or
Repair
Replacement of
PCB
Replacement
Replacement, repair
of temperature
sensor 1
Replacement of
PCB
(defective element, broken Replacement, repair
of temperature
sensor 2
Replacement of
PCB
Replacement, repair
of temperature
sensor
Replacement of
PCB
Repair
Repair
Replacement, repair
Replacement
Repair
Reference
page
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