Electronic Parts Troubleshooting Guide - LG LS-M3021CL Service Manual

Electronic Parts Troubleshooting Guide

1. Product does not operate at all.
(* Refer to Electronic Control Device drawing and Schematic diagram.)
Check the voltage of power(About AC 220V/AC240V, 50Hz)
• Main power's voltage
• Voltage applied to the unit
• Connecting method of Indoor/Outdoor connecting cable
• Check PWB Ass'y
- Fuse
- Pattern damage
- Varistor(ZNR01J)
Check the connection housing for contacting
• Connector related to CN-POWER
• Connector related to CN-MOTOR
• Connector contacting of Outdoor Fan/Compressor
• Display PWB Ass'y Check
Items
• Power Transformer
(Outdoor unit)
- Input Voltage
- Output Voltage
• IC01D(7812) Output (Outdoor unit)
• IC02D(7805) Output (Outdoor unit)
IC04D(7805) Output (Indoor unit)
• IC01A(KIA7036, Reset IC)
OSC01B(8MHz) (Indoor unit)
• IC01A(KIA7036, Reset IC)
OSC01B(4MHz) (Outdoor unit)
Turn off Main Power
Turn on Main Power
Does "beeping" sound is made from the Indoor Unit?
NO
PCB Board Operation Check
- About AC220V/240V ± 10% - Check the power voltage
- About AC14 ± 3V
• DC + 12V
• DC + 5V
• Voltage of Micom No. 2, (Indoor unit)
(DC +4.5V over) and Soldering condition.
No. 5 (Outdoor unit)
(After 10 seconds)
Primarily, the operating condition of Micom is OK.
Check each load(Indoor/Outdoor Fan Motor,
Compressor, Stepping Motor) and contacting
condition of related connector
Content
- 55 -
YES
Remedy
• Replace Trans
• Replace IC01D
(Outdoor unit)
• Replace IC02D
(Outdoor unit)
IC04D(Indoor unit)
• Replace faulty parts