Service manual

1) Checklist :

(1) Is AC voltage between “L1” and “1” of outdoor terminal block is normal?

(Input voltage within ±10% range)

If the Output is not checked, check “L1” and “1” of Indoor Terminal Block.

(2) Are connectors linked correctly to the outdoor PCB?

(CN71, CN76, CN72, CN11)

2) Troubleshooting procedure

1-1 No Power-Initial diagnosis in case of the Outdoor Unit PCB of US12AA(B)MCF

Check AC Output between “L1” and “1” of the outdoor terminal block

Is voltage rating between #1 and #3 (CN72) normal?

Is AC voltage between #1 and #3 (CN11) ( = )AC 17V?

Is DC voltage between “I” and “G” (IC01) normal?

Is DC voltage between “G” and “O” (IC01) ( = ) DC 12V?

Is DC voltage between “G” and “O” (IC02) ( = ) DC 5V?

Is the power supply normal?

Check the other connection parts

Check F701, F702 is open

Replace PCB

TRANS is abnormal.

Replace TRANS

BD71 or D101 is abnormal.

Replace PCB

IC01(KA7812) is abnormal.

Replace PCB

IC02 is abnormal.

Replace PCB

MICOM or LED is abnormal.

YES

Is LED 01 (GRN) on?

AS07AS(6)MA SM_E_15774 2/12/04 9:19 PM Page 15