Mitsubishi Electric PUZ-SWM60VAA Service Manual page 37

Symptoms: Nothing is displayed on the remote controller. 2
Check the voltage between S1 and S2 on the terminal block
of the indoor unit which is used to connect the indoor unit
and the outdoor unit.
198 to 264 VAC?
YES
Check the status
of the indoor controller
board LED3 display.
Blinking.
Check the refrigerant address of
the outdoor unit. (SW1-3 to 1-6)
Is the refrigerant
address "0"?
YES
Check the LED display of the
outdoor unit after turning on the
main power again.
Is anything displayed?
YES
Is "EA" or "Eb"
displayed?
YES
Check the voltage between S2
and S3 on the terminal block of
the outdoor unit.
17 to 28 VDC?
YES
OCH809A
Diagnosis flow
NO
Not lighting.
Check the looseness or disconnection
of the indoor/outdoor connecting wire.
Are there looseness or
disconnection of the indoor/
outdoor connecting wire?
NO
NO
NO
NO
Is "E8" displayed?
Can the unit be restarted?
Can all the indoor
unit be operated?
NO
Cause
YES
• Breaking or poor
contact of the indoor/
outdoor connecting
wire
• Normal
Only the unit which
has the refrigerant
address "0" supplies
power to the remote
controller
• Defective outdoor
controller circuit
board
YES
• Defective outdoor
controller circuit
NO board
NO
• Defective indoor
controller board
YES
• Influence of
electromagnetic
noise
• Defective outdoor
power circuit board
• Defective indoor
power board
37
LED display of the indoor
controller board
LED1:
LED2:
LED3: or
Inspection method and
troubleshooting
• Fix the breaking or poor
contact of the indoor/outdoor
connecting wire.
• Set the refrigerant add-
ress to "0". In the case
of the multiple outdoor
units control, recheck the
refrigerant address again.
• Replace the outdoor
controller circuit board.
• Replace the outdoor
controller circuit board.
• Replace the indoor controller
board of the indoor unit which
does not operate.
• Not abnormal.
There may be the influence
of electromagnetic noise.
Check the transmission wire
and get rid of the causes.
• Replace the outdoor
power circuit board.
• Replace the indoor
power board.