Service Manual 49
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 220V, 60Hz)
(About AC 220/240V, 50Hz)
• Main power's voltage
• Voltage applied to the unit
• Connecting method of Indoor/Outdoor connecting
cable
• Check PWB Assembly
- Fuse
- Pattern damage
- Varistor(ZNR01N)
Check the connection housing for contacting
• Connector related to CN-POWER1, 2
• Connector related to CN-MOTOR
• Connector contacting of Outdoor Fan/Compressor
• Display PWB Assembly Check
Check each load(Indoor/Outdoor Fan Motor,
Compressor, Stepping Motor) and contacting
condition of related connector
Main PCB Board Operation Check
Items
• SMPS Transformer
(Indoor unit)
- Input Voltage
- Output Voltage
• IC04D(7805) Output
• IC01A(Reset IC)
OSC01B(8MHz)
• Replace Trans
• Replace IC04D
• Replace faulty parts
- About AC220V/240V±10% - Check the power voltage
- About DC12V
• DC +5V
• Voltage of Micom No. 36,
(DC +4.5V over) and Soldering condition.
Content Remedy
NO
YES
(After 10 seconds)