LG GR-349STQA.CTIQRAN Service Manual page 22

4) LOAD/BUZZER OPERATION, DOOR OPENING SENSING CIRCUIT
(1) LOAD OPERATION CHECK
KIND OF LOAD
MEASURING POINT (IC4)
ON
STATE
OFF
• 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.
MEASURING POINT
REFRIGERATOR DOOR
CLOSE
OPEN
• 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.
COMP,
COMP COOLING FAN
No.11
- 22 -
FAN MOTOR
No.12
below 1V
12V
NO.13 OF IC 1 (MICOM)
5V(S/W of A , B is OFF state)
0V(S/W of A , B is ON state)
DEFROSTING HEATER
No.13