For Service Technician Use Only
COMPONENT TESTING (Cont.)
3-8
n
Low Profile Microwave Hood Combination
Components
Test/Results
Hood Exhaust Fan Motor
1.
Unplug microwave oven or disconnect power.
2.
Remove wire leads.
3.
Measure resistance:
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High Speed—Normal: Red (RD) and Blue (BU) wires: 70 to 170 ohms (approximate);
Blue (BU) and Black (BK) wires: 20 to 100 ohms (approximate)
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Middle Speed-Normal: Grey (GY) and Blue (BU) wires: 50 to 130 (approximate)
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Low Speed—Normal: White (WH) and Blue (BU) wires: 60 to 160 ohms (approximate);
Blue (BU) and White (WH) wires: 80 to 150 ohms (approximate)
HF NTC Thermistor
1.
If “NTC SHORT, CALL FOR SERVICE” or “NTC OPEN, CALL FOR SERVICE” scrolls on display,
unplug microwave oven or disconnect power.
2.
Measure hood thermistor:
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Normal: 10 k ohms +/-5% at 77°F (25°C)
AC Line Filter Board
1.
Unplug microwave oven or disconnect power.
2.
Remove wire leads.
3.
Measure resistance:
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Normal: L-IN to L-OUT (coil): Less than 1 ohm; N-IN to N-OUT (coil): Less than 1 ohm
Thermostats
NOTE:
Refer to “Parts Layout” for opening and closing temperatures.
1.
Unplug microwave oven or disconnect power.
2.
Remove wire leads.
3.
Measure continuity:
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Normal: Continuity
Open Door Switch
1.
Unplug microwave oven or disconnect power.
2.
Remove wire leads.
3.
Make sure the switch is pressed
4.
Measure resistance:
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Normal: >1M ohm
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Abnormal: <5 ohm
Open Door Switch
1.
Unplug microwave oven or disconnect power.
2.
Remove wire leads.
3.
Measure resistance:
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Normal: 40 to 60 ohms (approximate)
35
51
P5
Cavity Thermostats
Magnetron Thermostat
Switch
