Indoor Unit - Mitsubishi Electric MSZ-HR25VF-E1 Service Manual

10-3. INSTRUCTION OF TROUBLESHOOTING
Start
Indoor unit oper-
ates.
Outdoor unit
does not operate.
Outdoor unit Outdoor unit
operates only does not
in Test Run operate even
operation. in Test Run
operation.
Check room Refer to "How
temperature
to check
thermistor.
inverter/com-
Refer to 10-
pressor".
7. "Test point
diagram and
voltage".
Left lamp
blink on and off
at 0.5-second
intervals
Cause:
Indoor/Outdoor
unit
• Miswiring or
trouble of serial
signal
Refer to 10-
6. "How to
check mis-
wiring and
serial signal
error".
OBH822
Indoor unit operates.
Outdoor unit does
not operate normally.

Indoor unit

Unit does not
operates, when
operate nor-
EMERGENCY
mal operation
OPERATION
in COOL or
switch is pressed.
HEAT mode.
Refer to Refer to 10-6.
"Check of R.V. "Check of remote
coil". controller and
indoor electronic
control P.C. board".
Left lamp Left lamp
2-time blink 3-time blink
Cause: Cause:
Indoor unit Indoor unit
• Trouble • Trouble of
of room indoor fan
temperature motor
/ indoor coil
thermistor
Check room Refer to 10-
temperature 6. "Check
thermistor of indoor fan
and indoor motor".
coil thermis-
tor. Refer to
10-7."Test
point diagram
and voltage".
Indoor unit does
not receive the
signal from re-
mote controller.
Indoor unit does
not operate, when
EMERGENCY
OPERATION
switch is pressed.
1. Check indoor/outdoor connect-
ing wire.
2. Check if the power is supplied to
indoor unit.
•
If power supply voltage is detected,
refer to 10-6. "Check of indoor
P.C. board and indoor fan motor".
•
If power supply voltage is not
detected, refer to outdoor unit
service manual.
Left lamp Left lamp
4-time blink 5-time blink
Cause: Cause:
Indoor unit Outdoor unit
• Trouble • Outdoor
of indoor power sys-
unit control tem abnor-
system mality
Replace the Refer to
indoor elec- "How to
tronic control check
P.C. board. inverter/com-
pressor".
19
OPERATION INDICATOR
lamp on indoor unit is
blinking ON and OFF.
"Test Run operation"
means the operation
within 30 minutes after
EMERGENCY OPERA-
TION switch is pressed.
If blinking of OPERATION
INDICATOR lamp cannot be
checked, it can be checked
with failure mode recall
function.
Refer to outdoor unit
service manual.
Left lamp Left lamp
7-time blink
6-time blink
Cause:
Cause:
Outdoor unit Outdoor unit
• Trouble of • Trouble
thermistor in of outdoor
outdoor unit control
system
Refer to Replace the
"Check of inverter P.C.
outdoor ther- board or
mistors". the outdoor
electronic
control P.C.
board.
Left lamp
14-time blink
or more
Cause:
Outdoor unit
• Other ab-
normality
Check "Flow
chart of the
detailed
outdoor unit
failure mode
recall func-
tion."