Illustration Component Test Results
Thermal cutout
31866P01 ...............
B5684121...............
Disconnect all wires from TCO.
Measure resistance across terminals.
Oven TCO . ............................................
Magnetron TCO........................................
Open at 300 °F (149 °C) and closed at
257 ° F (125 °C)
Open at 280 °F (137°C) and closed at
180
°F (82°C)
Diode
Discharge Capacitor
Remove diode lead from capacitor and
connect ohmmeter.
Reverse leads for second test.
in one direction and 50KΩ or more in
the opposite direction.
NOTE: Ohmmeter must contain a
battery of 6 volts minimum.
MT2
MT1 GA TE
Triac Disconnect wires to triac.
Measure resistance from:
MT1 to MT2 ..............................................
MT1 to Gate..............................................
MT2 to Gate..............................................
All terminals to ground..............................
Caution - Do not operate oven with
wire to terminal MT2 removed.
Approximately 60 Ω
Triac 1 (top) is for motors
Triac 2 (middle) is for heater element
Triac 3 (bottom) is for microwave
Voltage check measure voltage from:
MT1 to Gate..............................................
0.8 VAC when energized. If no
voltage, check H.V. board and wiring.
Capacitors – 0.65 µf
Discharge Capacitor
Remove wires from capacitor terminals and
connect ohmmeter, set on highest
resistance scale to terminals.
Also check between each terminal and
capacitor case.
Between Terminals: Meter should
momentarily
return to over 5 M Ω
occurs, replace capacitor.
Snubber assembly Disconnect wires to snubber.
Measure resistance across terminals ..........
Magnetron
Discharge Capacitor
Remove wires from magnetron and
connect ohmmeter to terminals. Also check
between each terminal and ground.
Between Terminals: Less than 1 Ω
Each terminal to ground measures
Note: This test is not conclusive. If
oven does not heat and all other
components test good replace the
magnetron and retest.
Microwave blower
motor
Remove all wires from motor.
Measure resistance across coil.
Approximately 30
Ω
Power relay Coil voltage – unit running
Terminal 0 to 1..........................................
Coil resistance
Terminal 0 to 1..........................................
(line voltage)
21 K Ω
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitors
before following any disassembly procedures.
B5684123 ..............
Fan TC
............................................O .
Open at 350 °F (177°C) and closed at
17 °F (-8°C)
