Indoor Unit - Mitsubishi Electric MSZ-AP25VG Service Manual

10-3. INSTRUCTION OF TROUBLESHOOTING
1. Check of the unit.
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 10-7.
pressor".
"Test point
diagram and
voltage".
Upper lamp Upper lamp
Flash on and 2-time fl ash
off at 0.5-sec- Cause:
ond intervals

Indoor unit

Cause: • Trouble
Indoor/Outdoor of room
unit temperature
• Miswiring or / indoor coil
trouble of thermistor
serial signal
Refer to Check room
10-6. "How temperature
to check mis- thermistor
wiring and and indoor
serial signal coil thermis-
error". tor. Refer to
10-7."Test
point diagram
and voltage".
OBH788
Indoor unit operates.
Indoor unit does
Outdoor unit does
not receive the
not operate normally. signal from re-
mote controller.
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
4-time fl ash
3-time fl ash
Cause:
Cause:
Indoor unit
Indoor unit
• Trouble
• Trouble of
of indoor
indoor fan
unit control
motor
system
Refer to Replace the
10-6. indoor elec-
"Check of tronic control
indoor fan P.C. board.
motor".
OPERATION INDICATOR
lamp on the indoor unit is
fl ashing ON and OFF.
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
6-time fl ash
5-time fl ash
Cause:
Cause:
Outdoor unit
Outdoor unit
• Trouble of
• Outdoor
thermistor in
power sys-
outdoor unit
tem abnor-
mality
Refer to Refer to
"How to "Check of
check outdoor ther-
inverter/com- mistors".
pressor".
22
NOTE: The indoor unit does not
operate by smartphone,
refer to 10-3.2."Check of
Wi-Fi Interface".
"Test Run operation" means the
operation within 30 minutes af-
ter EMERGENCY OPERATION
switch is pressed.
If blinking of OPERATION INDI-
CATOR lamp cannot be checked,
it can be checked with failure
mode recall function.
Refer to outdoor unit service manual.
Upper lamp Upper lamp
7-time fl ash 14-time fl ash
Cause: or more
Outdoor unit Cause:
• Trouble of Outdoor unit
outdoor con- • Other ab-
trol system normality
Replace the Check "Flow
inverter P.C. chart of the
board or detailed
the outdoor outdoor unit
electronic failure mode
control P.C. recall func-
board. tion."