Cautions To Be Observed When Troubleshooting - Panasonic NN-V653WF Service Manual

to determine operating conditions and output necessary to control
PWM signal to the inverter Power Supply to control output power.
3.3. Inverter turbo defrost
When this Auto Control feature is selected and the Start Pad is tapped:
1. The digital programer circuit determines the power level and
cooking time to complete cooking and indicates the operating
state in the display window. Table shows the corresponding
cooking times for respective serving by categories.
2. When cooking time the display window has elapsed, the oven
turns off automatically by a control signal from the digital
programmer circuit.
4. CAUTIONS TO BE OBSERVED WHEN
TROUBLESHOOTING
Unlike many other appliances, the microwave oven is a high voltage, high current device. It is
free from danger in ordinary use, though extreme care should be taken during repair.
Caution
Servicemen should remove their watches whenever working close
to or replacing the magnetron.
4.1. Check the grounding
Do not operate on a two wire extension cord. The microwave oven is designed to be grounded
when used. It is imperative, therefore, to ensure the appliance is properly grounded before
beginning repair work.
4.2. 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 current for the magnetron tube. Though it is free from danger in
ordinary use, extreme care should be taken during repair.
The aluminum heat sink is also energized with high voltage (HOT),
so do not touch when the AC input terminals are energized. The
power devices Collector is directly connected to the aluminum heat
sink.
The aluminum heat sink may be HOT due to heat energy, therefore,
extreme care should be taken during servicing.
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