Indoor Unit - Mitsubishi Electric MSZ-FD25VA 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 10-7.
pressor".
"Test point
diagram and
voltage".
All lamps POWER lamp
Flash on and Flash on and
off at 0.5-sec- off at 0.5-sec-
ond intervals ond intervals
Cause: Cause:

Indoor unit

Indoor/Outdoor
• The horizon- unit
tal vane is • Miswiring or
not installed trouble of
correctly. serial signal
Refer to Refer to
10-6. 10-6. "How
"Check of in- to check mis-
stallation of wiring and
the horizon- serial signal
tal vane". error".
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
receiver P.C.
board".
POWER lamp POWER 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
temperature 10-6.
thermistor "Check of
and indoor indoor fan
coil thermis- motor".
tor. Refer to
10-7. "Test
point diagram
and voltage".
"Test Run operation" means
the operation within 30 minutes
after EMERGENCY OPERA-
TION switch is pressed.
Indoor unit does
OPERATION INDICATOR
not receive the
lamp on the indoor unit is
signal from re-
fl ashing on and off.
mote 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
electronic control P.C.
board and indoor fan
motor".
POWER lamp POWER lamp
4-time fl ash 5-time fl ash
Cause: Cause:
Indoor unit Outdoor unit
• Trouble • Outdoor
of indoor power
unit control system
system abnormality
Replace the Refer to
indoor elec- "How to
tronic control check
P.C. board. inverter/com-
pressor".
24
If blinking of OPERATION INDI-
CATOR lamp cannot be checked,
it can be checked with failure
mode recall function.
PLASMA lamp 2-time
flash
Cause:
• Trouble of PLASMA
operation
Refer to 10-6. "Check of
PLASMA operation".
Refer to outdoor unit service manual.
POWER lamp POWER lamp
7-time fl ash
6-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.
POWER lamp
14-time fl ash
Cause:
Outdoor unit
• Other ab-
normality
Check "Flow
chart of the
detailed
outdoor unit
failure mode
recall func-
tion."