Daewoo KOR-137B Service Manual page 27

3. When there is no microwave oscillation
1) When touching the
Fan motor does not rotate, but cook indicator in display comes on.
- Check method
STATE
RELAY 2 ON
RELAY 2 OFF
2) When touching the
Fan motor and turntable rotate and cook indicator in display comes on.
- Check method
STATE
RELAY 1 ON
RELAY 1 OFF
4. When the door is opened during operation, the count down timer does not stop.
CN1
-Check method
STATE
1) DOOR OPEN
2) DOOR CLOSED
CHECK NO
1 Check the stage (ON, OFF) of the door open monitor switch by
resistance measurement.
5. When the digital clock does not operate properly.
Refer to Circuit Diagram.
POINT
IC 1 PIN 8
* If clock does not keep exact time, you must check resistor R20 and zener diode ZD2.
START pad, oven lamp does not turn on.
RY2
D10
(TRAY
LAMP)
RY2
POINT
START pad, oven lamp turns on.
RY1
D8
(M/W)
RY1
POINT
A
1
2
R10
D.O.M SW
POINT
METHOD
B
Q10
A
5VDC
GND
B
Q9
A
5VDC
GND
B
R1
C1 R9 C2
+5V
A
OPEN
CLOSE
WAVE FORM
T: 16.67ms(60Hz)
26
A
42
B
GND
12VDC
A
41
B
GND
12VDC
27
B
5VDC
GND
REMEDY
Replace door open monitor
switch.