Samsung ACH1800E Technical Manual page 166

Fault Diagnosis by Symptom
G EC18 : When the trouble is found on the part related to power system of indoor unit.
Check point :
- Indoor unit AC220V~AC240V input voltage, DC12V output, DC5V output, output voltage of pin no.2 and 3 of CN15.
- Power transformer, F101, F102, F701
After checking the correct connection between
indoor unit and outdoor unit, and check again
Is the voltage of pin no.1 and 3 of CN1
AC220V~AC240V?
YES
No trouble on F101, F102, F701?
YES
DC12V output?
YES
DC5V output?
YES
No trouble on the power system and
finish the test
(Cont.)
NO
Check the connection wire of indoor and
outdoor and then replace indoor unit PCB
NO
NO
NO
Check and replace IC02
Check and replace power
transformer
TROUBLE SHOOTING & ERROR MODE
Replace fuse
NO
No trouble on power
transformer AC output?
YES
Check and replace IC101
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