Panasonic NN-C2000P Service Manual page 20

NN-C2000P / NN-C2000W
connector (CN6) from the DPC otherwise a false reading
may be indicated.
NOTE 2: If checking an oven sensor thermistor just after
the microwave oven has been operating, the sensor of
course won't be room temperature. In this case the sensor
must be removed and allowed to cool down to the 10°C to
30°C range.
9.9. Humidity Sensor and digital
programmer circuit
1. Check across sensor heater terminals. Normal cold
resistance should read approx. 4.5 ohm.
2. In order to determine if the Auto/Humidity Sensor function
of the digital programmer circuit is in working order or not,
do the following test.
a. Place a water load in the oven.
b. Unsolder 2 black wires connected to sensor terminals.
c. Tap Sensor Reheat Pad to set auto sensor cooking and
tap Start Pad.
d. About 10 seconds after Start Pad is touched, short 2
black wires for 5 seconds and then remove them.
Before shorting the 2 black wires you can watch the
sensor heater glow red.
e. Approx. 75 seconds after the Start Pad is pressed (T0
TIME), short the 2 black wires again.
f. "AUTO" should disappear in display window and
following digits (see chart) should appear indicating
**balance of cooking time (T2 TIME). The time should
start to count down and oven should shut off when the
time has elapsed.
The Auto Sensor function in the digital programmer circuit is
working in order if above condition is obtained.
9.10. Oven temp sensor thermistor
This sensor monitors the heat produced by the heater circuit
and maintains the oven temperature the user had selected.
Normal room temperature, especially in a kitchen can vary
anywhere from 10°F to 30°F. The reading across the oven
sensor thermistor should be within 100K ohm to 500K ohm
when reading in an area within the 10°F to 30°F room
temperature range.
If the resistance reading is out of the range stated here, the
sensor is detective and must be replaced.
NOTE 1: When measuring resistance disconnect the 4-pin
connector (CN3) from the DPC otherwise a false reading
may be indicated.
NOTE 2: If checking an oven sensor thermistor just after
the microwave oven has been operating, the sensor of
course won't be room temperature. In this case the sensor
must be removed and allowed to cool down to the 50°F to
90°F range.
20