Panasonic NN-CT577SEPG Service Manual page 19

12.3 roubleshooting (other problems)
Symptom
1. Microwave output is low.
Oven takes a long time to cook food.
2. Loud Buzzing noise can be heard.
3. Turntable motor does not rotate.
4. Oven stops operation during cooking
cycle.
5. Oven returns to "plug in" state 9
seconds after the start pad is
pressed in sensor cooking mode.
6. Oven lamp and turntable motor
turn-on when the microwave oven is
plugged in with the door closed.
12.4 roubleshooting the inverter (U) & magnetron
. This oven is programmed with a self diagnostics failure code system which will help for troubleshooting.
H95, H97, H98 and H99 are the provided failure codes to indicate magnetron and inverter circuit problem areas.
This section explains failure codes of H95, H97, H98 and H99. First, you must program the DPC into TEST MODE,
Press Timer pad twice - Press Start pad once - Press Timer pad once - Press Micro Power pad once. Program unit
for operation. H95, H97, H98, H99 appears in the display window a short time after the start key is pressed and
there is no microwave oscillation.
12.5 Troubleshooting the inverter (U) & magnetron
Cause
1. Decrease in power source volt-
age.
2. Open or loose wiring of magne-
tron filament circuit causing inter-
mittent oscillation.
3. Ageing of magnetron
1. Loose fan or fan motor
. Open or loose wiring of turntable
motor.
2. Defective turntable motor
1. Open or loose wiring of primary
and secondary latch switch.
1. Open steam sensor circuit.
2. Defective steam sensor.
1. Maladjusted or loose wiring of
secondary latch switch.
2. Defective secondary latch switch.
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Correction
Consult electrician.
Refer to output test procedures.
Change magnetron
Adjust door and latch switches.
Adjust door and latch switches.