Complete the following steps before checking microwave circuitry:
1. Check the line voltage, household fuse or circuit breaker.
2. Check for loose wiring or mis-wiring within microwave.
3. Disconnect white wire from high-voltage transformer and discharge high-voltage capacitor.
NOTE: 1. All testing must be done with an ohmmeter having a sensitivity of 20,000 ohm per volt
or greater and powered by at least a 9-volt battery.
2. All operational checks with microwave energy must be done with a load
(1 liter water in a measuring glass cup) in the microwave oven.
NOTE: As low voltage transformer is energized, relays will close and complete circuit.
N
L
FUSE 20A
OVEN TCO
WH
WH/WH
BK
BK
BL/BL/BK
1. UNIT IS PLUGGED IN
CLOCK DISPLAY ON.
POWER
TRANS
3
1
2. MICROWAVE
COOKING ON
RY 1
O.L
3. VENTOR MOTOR ON
4. COOKTOP LAMP
ON
MGT TCO
N
OVEN TCO
WH
WH/WH
3
5
N
L
FUSE 20A
OVEN TCO
WH
OVEN LAMP
WH/WH
CN2
CN2
CN2
CN2
CN2
CN2
CN4
CN2
CN4
CN2
CN2
CN2
BK
BK
BK
3
5
MGT TCO
RY 1
T.T.M
N
L
FUSE
20A
OVEN TCO
WH
TT MOTOR
WH/WH
BK
BK
BK
RD/RD/RD
3
5
MGT
TCO
PRIMARY
SW
RY 2
F.M
N
L
FUSE
20A
OVEN TCO
WH
FAN MOTOR
WH/WH
BK
BK
BK
RD
BN
YL
3
7
MGT
TCO
PRIMARY
SW
S.M
N
L
FUSE
20A
OVEN TCO
PRIMARY
COIL OF H.V.T
WH
PRIMARY OF H.V.T
WH/WH
BK
BK
BK
RD
BN
MGT
TCO
PRIMARY
SW
RY 10
RY 9
RY 8
V.M
L
FUSE 20A
BK
BK
BL/BK
BK
MGT TCO
N
OVEN TCO
WH
WH/WH
3
3
RY 6
C.L
L
FUSE 20A
BK
BK
BK/BK
BN
MGT TCO
10-7