Mitsubishi Electric MSZ-WN25VA - E1 Service Manual page 18

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".
Upper lamp
Flash on and
off at 0.5-sec-
ond intervals
Cause:
Indoor/Outdoor
unit
• Miswiring or
trouble of se-
rial signal
Refer to 10-
6. "How to
check mis-
wiring and
serial signal
error".
OBH764
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".
Upper lamp
Upper lamp
2-time fl ash
3-time fl ash
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
OPERATION INDICATOR
not receive
lamp on the indoor unit is
the signal from
fl ashing on and off.
remote controller.
Indoor unit does
not operate, when
EMERGENCY
OPERATION
switch is pressed.
1. Check indoor/out-
door connecting wire.
(Check if the power is
supplied to the indoor
unit.)
2. Refer to 10-6. "Check
of indoor P.C. board
and indoor fan motor".
Upper lamp
Upper lamp
4-time fl ash
5-time fl ash
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".
18
If blinking of OPERATION INDI-
CATOR lamp cannot be checked,
it can be checked with failure
mode recall function.
"Test Run operation" means
the operation within 30 minutes
after EMERGENCY OPERA-
TION switch is pressed.
Refer to outdoor unit service manual.
Upper lamp
Upper lamp
6-time fl ash 7-time fl ash
Cause: Cause:
Outdoor unit
Outdoor unit
• Trouble of • Trouble of
thermistor in outdoor con-
outdoor unit trol system
Refer to
Replace the
"Check of
inverter P.C.
outdoor ther-
board or
mistors".
the outdoor
electronic
control P.C.
board.
Upper lamp
14-time fl ash
or more
Cause:
Outdoor unit
• Other ab-
normality
Check "Flow
chart of the
detailed
outdoor unit
failure mode
recall func-
tion."