Microwave Testing Procedures - Jenn-Air JMW8527DA Series Service Manual

Microwave Testing Procedures

To avoid risk of electrical shock, personal injury or death; disconnect power to oven before servicing, unless
testing requires it.
Illustration
Oven light and socket
Transformer
Turntable
Magnetron
Thermal cutout
Interlock switch
Monitor
Secondary
Primary
Capacitor
Fan Motor
26
!
Component
Test continuity of receptacle terminals .
Measure voltage at oven light...............
Discharge Capacitor
Remove all wires from terminals.
Measure resistance from:
Primary Terminals................................
Secondary Terminals ...........................
Remove all wires from terminals.
Measure resistance from:
Terminal to terminal................................ Approximately 2238 Ω
Discharge Capacitor
Remove wires from magnetron and
connect ohmmeter to terminals. Also
check between each terminal and
ground.
Disconnect all wires from TCO.
Measure resistance across terminals.
Magnetron TCO ...................................
Cavity TCO ..........................................
Disconnect wires to switch.
With door open measure resistance
from:
Monitor...........................................
Secondary .....................................
Primary ..........................................
With door closed measure resistance
from:
Monitor....................................................
Secondary...............................................
Primary ...................................................
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.
Remove all wires from motor.
Measure resistance across coil ............... Approximately 63.6 Ω
16022821 Rev. 0
WARNING
Test Procedure Results
Indicates continuity with bulb screwed in.
120 VAC; see wiring diagram for terminal
identification. If no voltage is present at
oven light check wiring.
Less than 1 Ω
Approximately 85 Ω
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.
Open at 230°F (110°C) and
closed at 194°F (90°C)
Opens at 320°F (160°C)
Indicates continuity
Infinite
Infinite
Infinite
Indicates continuity
Indicates continuity
Between Terminals: Meter should
momentarily deflect towards zero then
return to over 5 MΩ. If no deflection
occurs, or if continuous deflection
occurs, replace capacitor.
Terminal to Case: Infinite resistance
©2004 Maytag Appliances Company