Whirlpool 1997 "E" Microwave Oven User Manual


 
3-7
© 1997 Whirlpool Corporation
Cooking Products Service Manual
Original March, 1997 4322167
Page 3-7
THE CONVECTION THERMISTOR
thermistor signal going back to the microcom-
puter causes the heater relay to open and
close, and cycles the heating element on and
off.
NOTE: Verify that the heating element is work-
ing correctly before replacing a thermistor.
The convection thermistor is located under
the circulation pulley cover and is used during
the convection operation of the oven. When
the temperature increases, the resistance of
the thermistor decreases. The thermistor re-
sistance is monitored by the microcomputer.
As the oven temperature rises and falls, the
TESTING
1. Set the ohmmeter to the
R x 10K
scale.
2. Remove the 6-pin connector from
the control circuit board and mea-
sure across terminals 5 & 6.
You should measure 155 k to
350 k @ 68˚F.
PHILLIPS
SCREW
SENSOR
COVER
CONVECTION
THERMISTOR
BRACKETS
CIRCULATION
PULLEY COVER