Specifications

Troubleshooting SiUS12-928_A
139 Service Diagnosis
Troubleshooting 18 class
Check No.06
Refer to P.152
Check No.07
Refer to P.153
Check No.09
Refer to P.154
Note: Refer to “Application of silicon grease to a power transistor and a diode bridge” on page 224 for
detail.
Make sure the power has been off for at least 30 seconds.
(R12299)
Caution
NO
Slightly dirty
NG
Too dirty
OK
NO
YES
NO
YES
∗ Fin thermistor
(Precaution before turning on the power again)
Turn off the power and turn it on
again to start the system.
Check the radiation fin
temperature.
Check No. 07
Check the installation condition.
NO
YES
YES
Above ?
Radiation fin dirty?
Thermistor as
specified in its characteristic
chart?
Check No. 06
Check the thermistor resistance
value.
Check No. 09
Check the outdoor unit fan
or related.
Error displayed again?
Has PCB been replaced?
Replace the fin thermistor.
Check if the silicon grease
applied properly on the
radiation fin. If not, apply it
(
∗ ). (See Note.)
Check the power transistor
and the radiation fin for
looseness. If they are found
to be fit tightly, replace the
outdoor unit PCB or the
power transistor.
Replace the outdoor unit
PCB.
Replace the fan motor.
Correct the connectors and
fan motor leads.
Clean up the radiation fin.
∗
Silicon grease
Part No.: 1 172698
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
18 class 90°C (194°F)