Unlike many other appliances, the microwave oven is high
voltage, high current device. 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. Please be sure to contact the chassis
ground side first and then short to the output terminal.
WARNING
There is high voltage present with high current capabilities in the
circuits of the primary and secondary winding and filament winding of
the high voltage transformer. It is extremely dangerous to work on or
near these circuits with the oven energized.
DO NOT measure the voltage in the high voltage circuit including
filament voltage of the magnetron.
WARNING
Never touch any circuit wiring with your hand nor with an insulated
tool during operation.
3.3. Part replacement.
When troubleshooting any part of component is to be replaced,
always ensure that the power cord is unplugged from the wall
outlet.
3.4. When the 18 Amp fuse is
blown due to the malfunction
of the monitor interlock
switch:
WARNING
When the 10 Amp fuse is blown due to malfunction of the short
switch, replace all of the components (Primary interlock switch,
Secondary interlock switch, Monitor interlock switch).
1. This
is
mandatory.
Refer
to
“Measurements
and
Adjustments” for the location of 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 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 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 hinges or magnetron
installed incorrectly, the microwave leakage can exceed more than
5mW/cm
2
. After repair or exchange, it is very important to check if the
magnetron and the door hinges are is correctly installed.
3 CAUTIONS TO BE OBSERVED WHEN
TROUBLESHOOTING
6
NE-1022F
