Panasonic NN-G335WF, Service Manual

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Unlike many other appliances, the microwave oven is high-
voltage, high-current equipment. Though it is free from danger
in ordinary use, extreme care should be taken during repair.
CAUTION
Servicemen should remove their watches and rings whenever working
close to or replacing the magnetron.
3.1. Check the grounding
Do not operate on a 2-wire extension cord. The microwave
oven is designed to be grounded when used. It is imperative,
therefore, to make sure it is grounded properly before
beginning repair work.
3.2. Warning about the electric
charge in the high voltage
capacitor
For about 30 seconds after the oven is turned off, an electric
charge remains in the high voltage capacitor.When replacing or
checking parts, remove the power plug from the outlet and
short the terminal of the high voltage capacitor (terminal of lead
wire from diode) to chassis ground with an insulated handle
screwdriver to discharge.
WARNING
There is high-voltage present, with high-current capabilities in the
circuits of the high voltage winding and filament winding of the high
voltage transformer. It is extremely dangerous to work on or near
these circuits with oven energized.
DO NOT measure the voltage in the high voltage circuit including
filament voltage of magnetron.
WARNING
Never touch any circuit wiring with your hand nor with an insulated
tool during operation.
3.3. When parts must be replaced,
unplug the power cord from
the wall outlet.
3.4. When the 8 Amp fuse is blown
due to the malfunction of
short switch:
WARNING
When the 8 Amp fuse is blown due to malfunction of the interlock
monitor switch, you must replace all of the components (Primary latch
switch, Door switch, Short switch).
1. This is mandatory. Refer to “Measurements and
Adjustments” for these switches.
2. When replacing the fuse, confirm that it has the appropriate
rating for these models.
3. When replacing faulty switches, be sure mounting tabs are
not bent, broken or otherwise deficient in their ability to hold
the switches.
3.5. Avoid inserting nails, wire, etc.
through any holes in the unit
during operation.
Never insert a wire, nail or any other metal object through the
lamp holes on the cavity or any other holes or gaps, because
such objects may work as an antenna and cause microwave
leakage.
3.6. Verification after repair
1. After repair or replacement of parts, make sure that the
screws of the oven, etc. are neither loose nor missing.
Microwave energy might leak if screws are not properly
tightened.
2. Make sure that all electrical connections are tight before
inserting the plug into the wall outlet.
3. Check for microwave energy leakage.
CAUTION OF
MICROWAVE RADIATION OF LEAKAGE
USE CAUTION NOT TO BECOME EXPOSED TO RADIATION
FROM THE MICROWAVE MAGNETRON OR OTHER PARTS
CONDUCTING MICROWAVE ENERGY.
IMPORTANT NOTICE
1.The following components have potentials above 2000V while the
appliance is operated.
* Magnetron
* High voltage transformer
* High voltage diode
* High voltage capacitor
Pay special attention to these areas.
2.When the appliance is operated with the door hinge or magnetron
adjusted incorrectly, the microwave leakage can exceed more than
5mW/cm
2
. After repair or exchange, it is very important to check that
magnetron and the door hinge is correctly installed.
3 CAUTIONS TO BE OBSERVED WHEN
TROUBLESHOOTING
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NN-G335WF