Panasonic NN-L750WB Service Manual page 36

heat sink.
The aluminium heat sink may be (HOT) due to heat energy,
therefore, extreme care should be taken during servicing.
WARNING FOR INVERTER POWER SUPPLY (U) GROUNDING
Check the high voltage inverter power supply circuit grounding.
This high voltage inverter power supply circuit board must have a
proper chassis ground, the inverter grounding bracket must be
connected to the chassis. If the inverter board is not grounded it
will expose very high voltages and cause extreme DANGER! Be
sure that the inverter circuit is properly grounded via the inverter
earth bracket.
WARNING! DISCHARGE THE HIGH VOLATGE CAPACITORS
For about 30 seconds after the oven is turned off, an electric charge
remains in the high voltage capacitors in the inverter power supply
circuit board.
When replacing or checking parts, remove the power plug from the
outlet and short the inverter output terminal of the magnetron
filament terminals to the chassis ground with an insulated handle
Figure 1
HV Inverter warning
Figure 2
Grounding of the inverter circuit board
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