LG AP-Z Series Service Manual page 39

2) No heating operation works
NO
Reset the power
ON/OFF S/W ON
Is the AC220V
(AC 240 V) between connector
(CN-outunit) and of Main
P.C.B
NO
Is the unit operating?
YES
Is it heating mode?
YES
Room temp <Set temp?
YES
Is the DC5V
at 14 pin of terminal MICOM
YES
Is the DC5V
at 18 pin of terminal MICOM
YES
Is the DC12V
at each terminal?
(RY-4WAY COIL)
YES
Is the
AC220V (AC 240 V) between connec-
tor(4WAY) and CN-outunit of Main
P.C.B
YES
Is the DC12V at
each terminal? (RY-COMP
COIL)
YES
Is the AC220V
(AC 240 V) between connector(CN-outunit)
and of Main
P.C.B
YES
Check the wiring diagram.
Electronic Parts Troubleshooting Guide
YES
Is the input power AC220V
(AC240V) at COMP magnetic coil
contactor?
Check the COMP magnetic
contactor of outdoor unit.
NO
Select the heating operation mode.
NO
Room temp. < Set temp. Setting
NO
Replacement MICOM
NO
Replacement MICOM
NO
Replacement IC02M
NO
Replacement RY-4WAY
NO
Replacement IC02M
NO
Replacement RY-COMP
NO
YES
Check the wiring
connection
Service Manual 39