13
COMPONENT TESTING PROCEDURES
Illustration
Component
Testing
Results
Magnetron TCO
Disconnect all wires from TCO.
Measure resistance across terminals.
Magnetron TCO.....................................
Closed at 257ºF (125ºC) and
Opens at 300ºF (149ºC)
Latch TCO
Disconnect all wires from TCO.
Measure resistance across terminals.
Latch TCO .............................................
Opens at 230ºF (110ºC) and
Closes at 150ºF (66ºC)
Cavity TCO
Disconnect all wires from TCO.
Measure resistance across terminals.
Cavity TCO............................................
Opens at 219ºF (104ºC)
Diode
Discharge Capacitor
Remove diode lead from capacitor and
connect ohmmeter.
Reverse leads for second test.
Infinite resistance should be
measured in one direction and 50K
or less in the opposite direction.
NOTE:
Ohmmeter must contain a
battery of 6 volts minimum.
Triac
Resistance Check
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
.
Infinite
Approximately
60Ω
Infinite
Infinite
Voltage Check
Measure voltage from:
MT1 to Gate
MT1 to MT2
0.8 VAC when energized.
0 volts when gate energized or closed.
Line volts when gate not energized or
open.
Capacitor
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 deflect towards zero then
return to over 5 M
. If no deflection
occurs, or if continuous deflection
occurs, replace capacitor.
Terminal to Case: Infinite resistance
Magnetron
Discharge Capacitor
Remove wires from magnetron and
connect ohmmeter to terminals. Also
check between each terminal and
ground.
Between Terminals: Less than 1
Each terminal to ground measures
Infinite resistance.
Note:
This test is not conclusive. If
oven does not heat and all other
components test good replace the
magnetron and retest.
Solenoid (Left, Right)
Disconnect connector from solenoid
Measure resistance across coil.................
Approximately 6-11
Stirrer motor
Remove all wires from motor.
Measure resistance across terminals ....
Approximately 12K
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
