LG GA-449 Service Manual ▷ View online
2) OSCILLATION CIRCUIT
CIRCUIT for occurring CLOCK which motivates the internal local element of IC1 to transmit and receive an information and
BASIC TIME for calculating time. Use a proper form for OSC 1. Because in case that SPECIFICATION is changed, the
calculated time in IC1 is changed or IC1 isn't able to operate.
BASIC TIME for calculating time. Use a proper form for OSC 1. Because in case that SPECIFICATION is changed, the
calculated time in IC1 is changed or IC1 isn't able to operate.
u
GA-479**L*,**Q*,**C*/449**L*,**Q*,**C*
3) RESET CIRCUIT
All the internal parts of MICOM(IC1) return to the initial condition when the early power ON or apply power again in MICOM
after temporary power failure. As a result, all the functions operate according to the early condition. At the early period of
power ON the "LOW" voltage is applied in the RESET terminal of MICOM for the fixed time. The RESET terminal is 5V
during the general operation.
after temporary power failure. As a result, all the functions operate according to the early condition. At the early period of
power ON the "LOW" voltage is applied in the RESET terminal of MICOM for the fixed time. The RESET terminal is 5V
during the general operation.
u
GA-479**L*,**Q*,**C*/449B**L*,**Q*,**C*
- 29 -
4) LOAD/BUZZER OPERATION, DOOR OPENING SENSING CIRCUIT
(1) LOAD OPERATION CHECK
u
GA-479**L*,**C*/449**L*,**C*
u
GA-479**Q*/449**Q*
u
GA-479**L*,**C*/449**L*,**C*
u
GA-479**Q*/449**Q*
- 30 -
LOAD
COMP
HEATER
LAMP
MEASURING POINT(IC7)
NO.16
NO.15
NO.14
STATE
ON
BELOW 1V
OFF
12V
LOAD
COMP
HEATER
LAMP
MEASURING POINT(IC7)
NO.16
-
NO.14
STATE
ON
BELOW 1V
OFF
12V
(2) DOOR OPENING PERCEPTION CHECK
u
GA-479**L*,**Q*,**C*/449**L*,**Q*,**C*
- 31 -
A
B
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)
(3)BUZZER OPERATION CHECK
u
GA-479**L*,**Q*,**C*/449**L*,**Q*,**C*
NOTE) In the cuse of Best model, BUZZER is in the LCD [Refer to DISPLAY CIRCUIT].
- 32 -
Tone(Beep~) when the button
Alam for open door
on the display is pushed
(beep-beep-beep)
OFF
IC1 ( A )
5V
IC1 ( B )
0V
MEASUREMENT
LOCATION
LOCATION
CONDITION
0.1s
0.5s
0V
5V
0V
5V
1.9kHz(Beep~)
0.5s
0.5s
0V
5V
0V
5V
1.9kHz(Beep~)
OFF
Click on the first or last page to see other GA-449 service manuals if exist.