Cautions To Be Observed When Troubleshooting; Check The Grounding; Warning About The Electric Charge In The High Voltage Capacitor; When Parts Must Be Replaced, Remove The Power Plug - Panasonic NN-S335BF Service Manual

6 CAUTIONS TO BE OBSERVED WHEN
TROUBLESHOOTING
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 whenever working close to
or replacing the magnetron.
6.1.

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.
6.2. 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.
6.3. When parts must be replaced,
remove the power plug from
the outlet.
6.4. When the 15 Amp fuse is
blown due to the operation of
short switch:
When the 15 Amp fuse is blown due to operation of the interlock
monitor switch, you must replace all of the components (Primary latch
switch, Door switch, Short switch and Power relay B (RY1)).
1. This is mandatory.
Measurement" 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.
6.5. 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.
6.6.

Confirm after repair

1. After repair or replacement of parts, make sure that the
screws of the oven, etc. are neither loose nor missing.
Microwaves 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. (Refer to procedure
for measuring microwave evergy leakage.)
MICROWAVE RADIATION
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
2
5mW/cm . After repair or exchange, it is very important to check that
magnetron and the door hinge is correctly installed.
9
NN-S335BF / NN-S335WF / NN-S335WM /
WARNING
Refer to "Adjustments
CAUTION
and