Cautions To Be Observed When Troubleshooting - Panasonic NN-A883WB Service Manual

leveland calculate the lengh of time it will take to cook the food.
NOTE: Auto Sensor Cooking is is successful with the foods and recipes found in the Auto
Sensor Cooking guide. Because of the vast differences in food composition, items not
mentioned in the cooking guide should be prepared using the power select and time features.
Please consult variable power microwave cook book for proceedures.
Explanation of the Auto Sensor Cooking process:
1. The shaded columns in Figure 1 indicate when the humidity
sensor heater is on.
2. During the 30 seconds period there is no microwave activity.
When calculating the T2 time by using the formula below, make
sure the 30 seconds is subtracted from the T0 time.
3. T1 time T0 time - 30 seconds.
4. T2 time when the steam escapes from the cooking container
placed in the oven,

8. Cautions to Be Observed When Troubleshooting

Unlike many other appliances, the microwave oven is a high voltage, high current is device.
Though it is free from danger in ordinary use, extreme care should be taken during repair.
Caution
Servicemen should remove their watches whenever working close
to or replacing the magnetron.
8.1. Check the grounding
Do not operate on a two wire extension cord. The microwave oven is designed to be used when
grounded. It is imperative, therefore, to ensure the appliance is properly grounded before
beginning repair work.
8.2. Inverter Warnings
DANGER, HIGH VOLTAGE AND HIGH TEMPERATURE (HOT/LINE) OF THE INVERTER POWER
SUPPLY (U)
This high voltage inverter power supply handles very high voltage
and very high current for the magnetron tube. Though it is free from
danger in ordinary use, extreme care should be taken during repair.
As you can see, it looks like a TV flyback transformer, however, the
current is extremely large and is therefore, dangerous due to this
high current and high voltage.
The aluminium heat sink is also energized with high voltage (HOT),
so do not touch when the AC input terminal is connected. The
power devices (Collector) is directly connected to the aluminium
heat sink.