Component Testing; Thermostats - Whirlpool MH3184XPB Service Manual

IMPORTANT: Before performing any tests on
the microwave oven, be sure to observe the
following:
• Unplug microwave oven or disconnect
power.
• Remove the lead wires from the related
component before conducting any of the
following tests.
• All operational checks using microwave en-
ergy must be done with the microwave oven
loaded with a minimum of 10 oz. (300 mL)
of water in a microwave-safe container.
Disconnect power before servicing.
Replace all parts and panels before operating.
Failure to do so can result in death or electrical shock.

THERMOSTATS

Refer to the following pages for the procedures
for accessing the thermostats:
Cavity Thermostat #3, page 4-5
Cavity Thermostat #2, page 4-9
Cavity Thermostat #1, page 4-12
Magnetron Thermostat, page 4-18
Exhaust Fan Thermostat, page 4-19

COMPONENT TESTING

Electrical Shock Hazard
• Conduct a microwave energy test af-
ter performing any tests or repairs to the
microwave oven.
• Check that all wire leads are in the correct
position before operating the microwave
oven.
• Grasp wire connectors when removing the
wire leads from microwave oven parts.
• All testing must be done with an ohmmeter
having a sensitivity of 20,000 ohms-per-
volt DC or greater and powered by at least
a 9-volt battery.
WARNING
1. Unplug microwave oven or disconnect
power.
2. Disconnect one of the wires from the
thermostat terminals.
3. Set the ohmmeter to the R x 1 scale.
4. Exhaust Fan Thermostat: Touch the ohm-
meter test leads to the thermostat termi-
nals. The meter should indicate an open
(infinite) circuit.
5. All Other Thermostats: Touch the ohm-
meter test leads to the thermostat termi-
nals. The meter should indicate a closed
(0 Ω) circuit.
5-1