Component Testing Procedures
!
WARNING
To avoid risk of electrical shock, personal injury or death, disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
October 2013
16500048
©2013 ACP, Inc.
2
Illustration
Component
Test
Results
Thermal Cutout
Disconnect all wires from TCO.
Measure resistance across terminals.
Cavity Thermal Fuse ......................................
Magnetron TCO .............................................
Open at 230° F (110° C).
Open at 320° F (160° C).
Diode Assembly
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
Ω
or more in
the opposite direction.
NOTE:
Test meter must contain a
battery of 6 volts minimum.
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
Ω
. If no deflection
occurs, or if continuous deflection
occurs, replace capacitor.
Terminal to Case:
Infinite resistance.
Magnetron
Discharge Capacitors
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
Infinite resistance.
NOTE:
This test is not conclusive. If
oven does not heat and all other
components test good replace the
magnetron and retest.
Stirrer Motor
Remove all wires from terminals.
Measure resistance from:
terminal to terminal ......................................
Approximately 10 K
Ω
.
Blower Motor
Remove all wires from motor.
Measure resistance from terminal to
terminal… .......................................................
Approximately 435
Ω
.
Fuse block / Filter
assembly
Power In terminals ......................................
Power Out terminals ...................................
230 VAC
230 VAC
If no power in, check power outlet
If no power out, check fuses
