Testing Procedures; Component Testing (Table) - Maytag JMV8186AA Series Service Manual

Testing Procedures

To avoid risk of electrical shock, personal injury or death; disconnect power to microwave and discharge capacitors
before servicing, unless testing requires power.
Illustration
High voltage
transformer
120 V
Primary
Low voltage
transformer
Magnetron
High voltage
capacitor
High voltage diode
Primary interlock
switch test
(Bottom switch)
Secondary interlock
switch test
(Top switch)
Interlock monitor
switch test
(Middle switch)
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Component
Discharge Capacitor
Disconnect connector and measure
continuity with meter on R x 1 scale:
Secondary
Secondary ..........................................
Filament ..............................................
Primary (High & Low)..........................
Filament
(Measure at room temp., or 68° F/20° C)
0 V
Measure continuity, meter on "High" scale:..
Primary winding to ground ..................
Filament winding to ground .................
Remove low voltage transformer from
control circuit board and check:
(Measure at room temp., or 68° F/20° C)
Between pins 1 and 2 (Input) ..............
Between pins 4 and 5 (19v output) .....
Between pins 7 and 8 (2.7v output) ....
Discharge Capacitor
Remove wires from magnetron and
connect ohmmeter to terminals. Also
check between each terminal and ground.
Discharge Capacitor
Remove wires from capacitor terminals
and connect ohmmeter to terminals, set
on highest resistance scale.
Also check between each terminal and
capacitor case..............................................
Discharge Capacitor
Remove diode lead from capacitor and
connect ohmmeter.
Reverse leads for second test.
Measure resistance between
terminals 1 and 2:
Door Open ...................................................
Door Closed.................................................
1
2
Measure resistance between
terminals 1 and 2:
Door Open ...................................................
Door Closed.................................................
Measure resistance between
terminals 1 and 2:
Door Open ...................................................
1
Door Closed.................................................
2
WARNING
Test Procedure
16026440
Results
Approximately 92 Ω
Continuity
Less than 1 Ω
Infinite Ω
Infinite Ω
Approximately 244 Ω
Approximately 11 Ω
Approximately 2 Ω
Between Terminals: Less than 1 Ω
Each terminal to ground: Infinite
resistance.
Note: This test is not conclusive. If
oven does not heat and all other
components test good replace the
magnetron and retest.
Between Terminals: Meter indicates
continuity for a short time, then 9 mΩ.
If meter indicates continuous
continuity, capacitor is shorted. If
meter indicates continuous 9 mΩ,
capacitor is open. Replace capacitor.
Terminal to Case: Infinite resistance
Infinite resistance measured in one
direction and several hundred kΩ
measured in the opposite direction.
NOTE: Ohmmeter must contain a
battery of 6 volts (minimum).
Open (Infinite)
Continuity
Open (Infinite)
Continuity
Continuity
Open (Infinite)
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