Mitsubishi Electronics MSZ-A09NA, MSY-A24NA, MSY-A15NA Instruction of troubleshooting, Operation

8-3. Instruction of troubleshooting

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Indoor unit operates. Outdoor unit doesn't operate.

Indoor unit operates. Outdoor unit doesn't operate normally.

Indoor unit doesn't receive the signal from remote controller.

OPERATION INDICATOR lamp on the indoor unit is flashing on and off.

Outdoor unit		Outdoor unit
operates only		doesn't
in Test Run		operate
operation.		even in
	w	Test Run
		operation.
			w
Check room		Refer to
temperature		"How to check
thermistor.		inverter/
Refer to 8-7.		compressor".
"Test point
diagram and
voltage".

Unit doesn't	Indoor unit
	operates, when
operate
	EMERGENCY
normal
	OPERATION
operation in
	switch is pressed.
COOL or
HEAT mode.

Refer to	Refer to 8-6.B
"Check of	"Check of
R.V. coil".	remote controller
	and receiver
	P.C. board".

Indoor unit doesn't operate, when

EMERGENCY

OPERATION switch is pressed.

1.Check indoor / outdoor connecting wire. (Check if the power is supplied to the indoor unit.)

2.Refer to 8-6.C"Check of indoor electronic control P.C. board and indoor fan motor".

If blinking of OPERATION INDICATOR lamp cannot be checked, it can be checked with failure mode recall function.

w

"Test Run operation" means the operation within 30 minutes after EMERGENCY OPERATION switch is pressed.

Refer to outdoor unit service manual.

Left lamp	Left lamp
Flash on and off	2-time flash
at 0.5-second	Cause:
intervals	Indoor unit
Cause:	• Trouble of
Indoor/	room temp-
Outdoor unit	erature/
• Mis-wiring	indoor coil
or trouble	thermistor
of serial signal
Refer to 8-6.	Check room
D "How to	temperature
check of	thermistor
mis-wiring	and indoor
and serial	coil thermis-
signal error".	tor.
	Refer to 8-7.
	"Test point
	diagram and
	voltage".

Left lamp	Left lamp	Left lamp	Left lamp	Left lamp	Left lamp
3-time flash	4-time flash	5-time flash	6-time flash	7-time flash	14-time flash
Cause:	Cause:	Cause:	Cause:	Cause:	Cause:
Indoor unit	Indoor unit	Outdoor unit	Outdoor unit	Outdoor unit	Outdoor unit
• Trouble of	• Trouble of	• Outdoor	• Trouble of	• Trouble of	• Other
indoor fan	indoor unit	power	thermistor	outdoor	abnormality
motor	control	system	in outdoor	control
	system	abnormality	unit	system

Refer to 8-6.	Replace the	Refer to	Refer to	Replace the	Check
A "Check of	indoor	"How to check	"Check of	inverter P.C.	"Flow chart of
indoor fan	electronic	inverter/	outdoor	board or	the detailed
motor".	control	compressor".	thermistors".	the outdoor	outdoor unit
	P.C. board.			electronic	failure mode
				control P.C.	recall function."
				board.

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