General Troubleshooting Chart - IVT AE-X12GR-N Service Manual

AEX12GRN

[5] GENERAL TROUBLESHOOTING CHART

1. Indoor unit does not turn on
Main cause
Cracked PWB.
(Cracked pattern)
Open-circuit in FU1 (250 V, 3
A), FU2 (250 V, 3 A)
2. Indoor unit fan does not operate
Main cause
Open-circuit in heat
exchanger thermistor (TH2)
(in heating operation)
Disconnected heat exchanger
thermistor (TH2) (in heating
operation)
3. Indoor unit fan speed does not change
Main cause
Remote control not designed
to allow fan speed change.
4. Remote control signal is not received
Main cause
Batteries at end of service life.
Batteries installed incorrectly.
Lighting fixture is too close, or flu-
orescent lamp is burning out.
Use Sevick light (Hitachi).
Operating position/angle is inap-
propriate.
Open-circuit or short-circuit in wir-
ing of light receiving section.
Defective light receiving unit.
Dew condensation on light receiv-
ing unit.
5. Louvers do not move
Main cause
Caught in sliding section.
Disconnected connector (DCNC,
DCND on relay PWB, louver
motor side)
Contact of solder on PWB
(connector section on PWB)
Inspection method
Check visually.
Check melting of FU1, FU2.
Inspection method
Measure thermistor resistance (dis-
mount for check).
Inspect connector on PWB.
Check thermistor installation condi-
tion.
Inspection method
Check operation mode.
Inspection method
Measure battery voltage.
Check battery direction.
Turn off light and check.
Check if Sevick light (Hitachi) is
used.
Operate within range specified in
manual.
Check if wires of light receiving
section are caught.
Check signal receiving circuit
(measure voltage between termi-
nals 2 and 3 of connector
BCN3B).
Check for water and rust.
Inspection method
Operate to see if louvers are
caught in place.
Inspect connectors.
Check visually.
Normal value/condition
There should be no cracking in PWB
or pattern.
There should be no open-circuit.
Normal value/condition
Refer to THERMISTOR TEMPERA-
TURE CHARACTERISTICS – 1
There should be no open-circuit or
faulty contact.
Thermistor should not be discon-
nected.
Normal value/condition
Fan speed should change except dur-
ing dehumidifying operation, ventila-
tion, light dehumidifying operation,
internally normal operation
Normal value/condition
2.5 V or higher (two batteries in series
connection)
As indicated on battery compartment.
Signal should be received when light
is turned off.
Signal may not be received some-
times due to effect of Sevick light.
Signal should be received within
range specified in manual.
Wires of light receiving section should
not have any damage caused by
pinching.
Tester indicator should move when
signal is received.
Signal should be received within
range specified in manual.
Normal value/condition
Louvers should operate smoothly.
Connectors or pins should not be dis-
connected.
There should not be solder contact.
3 – 6
Remedy
Replace PWB.
Replace PWB.
Remedy
Replace thermistor.
Replace thermistor.
Install correctly.
Remedy
Explain to user.
Remedy
Install new batteries.
Install batteries in indicated direc-
tion.
Change light position or install
new fluorescent lamp.
Replace light or change position.
Explain appropriate handling to
user.
Replace wires of light receiving
section.
Replace PWB.
Take moisture-proof measure for
lead wire outlet of light receiving
section.
Remedy
Remove or correct catching sec-
tion.
Install correctly.
Correct contacting section.