Panasonic Microwave Ovens with Inverters Technical Manual page 37

Symptom
The oven can be
6 programmed, but the timer
does not start to countdown.
The microwave output is low.
7 The oven takes too long to
cook.
The fan motor and the oven
8 lamp turn on when the door is
opened.
The oven does not operate. It
returns to plugged-in mode as
9
soon as the start pad is
pressed.
Loud buzzing noise can be
10
heard.
Turntable motor does not
11
rotate.
The Oven stops operation
12
during cooking.
The oven returns to plugged-
in mode after 10 seconds
13
elapse on the Auto-sensor
cooking mode.
Cause
1. Open or loose wiring of secondary switch.
2. Secondary switch alignment is off.
3. Defective secondary switch
1. Decrease in AC power source voltage.
2. Open or loose wiring of magnetron filament circuit.
(Intermittent oscillation)
3. Aging change of magnetron.
1. Shorted primary switch.
1. Open or loose wiring of temperature sensor.
(Thermistor)
2. Defective temperature sensor (Thermistor)
3. Defective DPC.
1. Loose fan.
2. Noisy fan
1. Open or loose wiring of turntable motor
2. Defective turntable motor
1. Open or loose connection of primary and secondary
switch
2. Operation of Thermal cutout (Thermistor)
1. Open or loose wiring of sensor terminal from DPC
2. Open steam sensor.
3. Defective DPC.
Table 2
32
Corrections
Adjust door and latch
switches
Check the outlet
voltage.
Perform microwave
power output test.
APH (USA) Models
only
Check for tight contact
of screw on thermistor,
and check the
connection on the
DPC.
Adjust the door and the
switches.