50 Room Air Conditioner

Troubleshooting Guide

Electronic Parts

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)
Indoor : 16MHz
Outdoor : 8MHz
• Replace SMPS
Module
• Replace IC01D
• Replace
IC02D(Indoor unit)
IC02D(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)