LG Electronics LAN091CNP, LAU091CNP, LAN121CNP Air Conditioner User Manual


 
Service Manual 63
Troubleshooting Guide
Electronic Parts (9k model)
Product does not operate at all.
(* Refer to Electronic Control Device drawing and Schematic diagram.)
Turn off Main Power
Turn on Main Power
Does "beeping" sound is made from the Indoor Unit?
Primarily, the operating condition of Micom is OK.
Check the voltage of power(About AC 115V, 60Hz)
Main power's voltage
Voltage applied to the unit
Connecting method of Indoor/Outdoor connecting
cable
Check PWB Ass'y(Outdoor unit)
- Fuse
- Pattern damage
- Varistor(ZNR01J)
Check the connection housing for contacting
Connector related to CN-POWER
Connector related to CN-FAN
Connector contacting of Outdoor Fan/Compressor
Display PWB Ass'y Check
Connector related to CN-DC/DC
Check each load(Indoor/Outdoor Fan Motor,
Compressor, Stepping Motor) and contacting
condition of related connector(including connecting
cable of Indoor/Outdoor Unit)
PCB Board Operation Check
Items
Power Transformer
(Outdoor unit)
- Input Voltage
- Output Voltage
IC01D(7812) Output
(Indoor/Outdoor unit)
IC02D(7805) Output
(Indoor unit)
IC03D(7805) Output
(Outdoor unit)
IC01A(KIA7036, Reset IC)
OSC01B(4MHz)
(Indoor/Outdoor unit)
Replace SMPS
Module
Replace IC01D
Replace
IC02D(Indoor unit)
IC03D(Outdoor unit)
Replace faulty parts
- About AC115V
±
10% - Check the power voltage
- About DC15V
±
3
DC
+
12V
DC
+
5V
Voltage of Outdoor unit Micom No. 18,
Voltage of Indoor unit Micom No. 43 and
soldering condition
Content Remedy
NO
YES
(After 20 seconds)