LG GR-349SQF.CEWQEHU, Service Manual

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4) LOAD/BUZZER OPERATION, DOOR OPENING SENSING CIRCUIT
(1) LOAD OPERATION CHECK
• If the DOOR-R is opened during FAN MOTOR is operated, FAN MOTOR is stopped immediately.
• The A , B of DOOR S/W-R is connected DOOR OPEN DETECTION CIRCUIT as follow.
• If the DOOR-R is opened or closed, then the DOOR S/W-R is ON/OFF, and the LAMP-R is ON/OFF,
and at the same time, S/W of the A , B of DOOR S/W-R for detection of DOOR-R open is ON/OFF.
(2) DOOR OPENING PERCEPTION CHECK
*NOTICE: If you would change DOOR S/W-R, must use the componenot of right PART NUMBER. Because there is a similar
type DOOR S/W-R of NOT MICOM MODEL, it's logic of the A , B of DOOR S/W-R is reversed.
• Even though LAMP-R is operated a normal ON/OFF according to DOOR S/W-R, but the MICOM couldn't detect a
DOOR-R opened or closed of lead wire of the A , B is abnormal or S/W of the A , B of DOOR S/W-R is abnormal.
• When DOOR-R open isn't detected : Even though DOOR-R is opened, FAN MOTOR couldn't stop.
When DOOR-R close isn't detected : Even though DOOR-R is closed, BUZZER sounds a DOOR OPEN ALARM.
check a lead wire of the A , B and DOOR S/W-R.
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KIND OF LOAD
COMP,
FAN MOTOR DEFROSTING HEATER
COMP COOLING FAN
MEASURING POINT (IC4) No.11 No.12 No.13
ON below 1V
STATE
OFF 12V
MEASURING POINT
NO.13 OF IC 1 (MICOM)
REFRIGERATOR DOOR
CLOSE 5V(S/W of A , B is OFF state)
OPEN 0V(S/W of A , B is ON state)