MICROWAVE OVEN
Troubleshooting & Technical Data
6-8
PROCEDURE
LETTER
COMPONENT TEST
TEST PROCEDURES
J
(CONTINUED)
4.
The corresponding segments of all digits do not light up; or they continue to light up.
5.
Wrong figure appears.
6.
A certain group of indicators do not light up.
7.
The figure of all digits flicker.
8.
The following symptoms indicate a defective LSI unit.
a.
When touching the keys on the touch screen, a certain key produces no signal at all.
b.
When touching a number key on the touch screen, two figures or more are displayed.
c.
When touching the keys on the touch screen, sometimes a key produces no signal.
c. Other possible problems caused by defective control unit.
1.
Buzzer does not sound or continues to sound.
2.
Clock does not operate properly.
3.
Cooking is not possible.
When testing is completed:
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
Reconnect all leads removed from components during testing.
5.
Reinstall the outer cabinet case, then reconnect power supply cord.
6.
Run the oven and check all functions.
KEY UNIT TEST
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is mak-
ing good contact, verify that the door sensing switch (stop switch) operates properly; that is the contacts are
closed when the door is closed and open when the door is open. If the door sensing switch (stop switch) is
good, disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the door
sensing switch is closed (either close the door or short the door sensing switch connecter). Use the Key
unit matrix indicated on the control panel schematic and place a jumper wire between the pins that corre-
spond to the STOP/CLEAR pad making momentary contact. If the control unit responds by clearing with a
beep the key unit is faulty and must be replaced. If the control unit does not respond, it is faulty and must
be replaced. If a specific pad does not respond, the above method may be used (after clearing the control
unit) to determine if the control unit or key pad is at fault.
5.
Reconnect all leads removed from components during testing.
6.
Reinstall the outer cabinet case, then reconnect power supply cord.
7.
Run the oven and check all functions.
P
P
P
P
rr
rr
ii
ii
o
o
o
o
rr
rr
tt
tt
o
o
o
o
S
S
S
S
e
e
e
e
rr
rr
ii
ii
a
a
a
a
ll
ll
N
N
N
N
u
u
u
u
m
m
m
m
b
b
b
b
e
e
e
e
rr
rr
1
1
1
1
2
2
2
2
0
0
0
0
0
0
0
0
1
1
1
1
5
5
5
5
4
4
4
4
G 1
G 2
G 3
G 4
G 5
G 6
G 7
G 8
G 9
G10
G11
G12
G13
G14
FRESH
VEGETABLES
BEVERAGE
BREAKFAST
LUNCH
POPCORN
FROZEN
SNACKS
RECIPES
QUICK ON/
START
FISH
SEAFOOD
POWER
LEVEL
KEEP
WARM
DINNER
DEFROST
HELP
BAKED
POTATOES
SENSOR
REHEAT
ADD
MINUTE
FROZEN
VEGTABLES
RICE
1
6
2
7
3
8
4
9
5
0
POULTRY
GROUND
MEAT
FROZEN
ENTREES
TIMER/
CLOCK
STOP
CLEAR