Panasonic NN-T704QF User manual

ORDERNO.SIMMC0407020A3
Microwave Oven
NN-T794AF / NN-T784SF / NN-T704QF / NN-T774SF / NN-
S784BF / NN-S784WF / NN-S754BF / NN-S754WF
QPQ(Australia&New Zealand)
Please fileand use thismanual together with the service manual for
Model NN-S560WF (ORDERNO. SIMMC0006012C3)
SPECIFICATIONS
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2004 PanasonicHome Appliances Microwave Oven (Shanghai)
Co., Ltd. / All rights reserved. Unauthorized copying and
distribution isaviolation of law.
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1. SCHEMATIC DIAGRAM
2. CAUTIONS TO BE OBSERVED WHEN
TROUBLESHOOTING
Unlike manyotherappliances, the microwave ovenis a high voltage, high current device. It is
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free fromdangerinordinaryuse, though extreme care shouldbe takenduring repair.
Caution
Servicemen shouldremove theirwatches whenever working close
to or replacing the magnetron.
2.1. Check the grounding
Donot operate on a twowire extension cord. The microwave ovenis designedtobe grounded
whenused. It is imperative, therefore, toensure the appliance is properlygroundedbefore
beginning repairwork.
2.2. Inverter warnings
DANGER, HIGH VOLTAGE AND HIGH TEMPERATURE (HOT/LINE) OFTHE INVERTER POWER
SUPPLY (U)
The high voltage inverter power supplyhandles veryhigh voltage
and current for the magnetron tube. Though itisfree from danger
inordinaryuse, extreme care shouldbe taken during repair.
The aluminum heat sink isalso energized with high voltage (HOT),
do not touch when the AC input terminalsare energized. The power
device Collector isdirectlyconnected to the aluminum heat sink.
The aluminum heat sink maybe HOTdue to heat energy, therefore,
extreme care shouldbe taken during servicing.
H.V. Inverterwarning
WARNING FOR INVERTER POWER SUPPLY (U) GROUNDING
Check the high voltage inverter power supplycircuitgrounding.
The high voltage inverter power supplycircuitboard must have a
proper chassisground. The inverter grounding bracket must be
connected to the chassis. Ifthe inverter board isnot grounded it
will expose the user to veryhigh voltages and cause extreme
DANGER!Besure that the inverter circuitisproperlygrounded via
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the inverter earth bracket.
Grounding of the invertercircuit board
WARNING!DISCHARGE THE HIGH VOLATGE CAPACITORS
For about 30 seconds after the oven isturned off, an electriccharge
remains inthe high voltage capacitors inthe inverter power supply
circuitboard.
When replacing or checking parts, remove the power plug from the
outlet and short the inverter output terminal of the magnetron
filament terminalsto the chassisground with an insulated handle
screwdriver to discharge. Please be sure to touch the chassis
ground side first and then short to the output terminals.
Discharging the high voltage capacitors
WARNING
There ishigh voltage present with high current capabilities inthe
circuits of the primaryand secondarywindings, choke coil and heat
sink of the inverter. Itisextremelydangerous to work on or near
these circuits with the oven energized. DO NOTmeasure the
voltage inthe high voltage circuitincluding the filament voltage of
the magnetron.
WARNING
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Never touch anycircuitwiring with your hand or with an insulated
tool during operation.
2.3. Part replacement.
Whenanypart orcomponent is tobe replaced, always ensure that the powercordis removed
fromthe wall outlet.
2.4. When the 10Afuse isblowndue to the operation of the short
switch:
WARNING
When the 10A250V fuse isblowndue to the operation of the
interlock monitor switch, replace all of the components (primary
latch switch, door switch, short switch and power relayB(RY1)).
1. Thisismandatory. Refer to “adjustments and measurements” for
the location of these switches.
2. When replacing the fuse, confirm that ithas the appropriate rating
for these models.
3. When replacing faultyswitches, be sure the mounting tabs are
not bent, broken or deficient intheirabilityto holdthe switches.
2.5. Avoidinserting nails, wire etc. through anyholes inthe unit
during operation.
Neverinsert a wire, nail oranyothermetal object through the lampholes on the cavityorany
holes orgaps, because suchobjects maywork as anantenna and cause microwave leakage.
2.6. Confirm after repair
1. After repairor replacement of parts, make sure that the screwsof
the oven, etc. are neither loose nor missing. Microwaves might
leak ifscrewsare not properlytightened.
2. Make sure that all electrical connections are tight before inserting
the plug into the wall outlet.
3. Check for microwave energyleakage. (Refer to procedure for
measuring microwave energyleakage).
CAUTION MICROWAVE RADIATION
USE CAUTIONNOTTO BECOME EXPOSEDTO RADIATIONFROM
THEMICROWAVE MAGNETRONOROTHERPARTS CONDUCTING
MICROWAVE ENERGY
IMPORTANTNOTICE
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The following components have potentialsabove 2000V whilethe
appliance isoperated.
-Magnetron
-High voltage transformer (Located on inverter (U))
-High voltage diodes (Located on inverter (U))
-High voltage capacitors (Located on inverter (U))
Payspecial attention to these areas.
When the appliance isoperated with the door hinges or magnetron
installed incorrectly, the microwave leakage can exceed more than
5mW/cm2. After repairor exchange, itisveryimportant to check if
the magnetron and the door hinges are correctlyinstalled.
2.7. Sharp edges
Caution
Please use caution when unpacking, installing or moving the unit,
as some exposed edges maybe sharp to the touch and cause
injuryifnot handled with care.
3. MEASUREMENTS AND ADJUSTMENTS
3.1. Adjustment of primarylatch switch, secondarylatch switch and
short switch.
1. Mount the Primarylatch switch, the secondarylatch switch and
the short switch to the door hook assemblyas showninILL.
NOTE:
Nospecificindividual adjustments during installation of the
Primarylatch switch, Secondarylatch switch or Short switch to
the door hook are required.
2. When mounting the door hook assemblyto the oven assembly,
adjust the door hook assemblybymoving itinthe direction of the
arrowsinthe illustration, so that the oven door will not have any
playinit. Check for playinthe door bypulling the door assembly.
Make sure that the latch keysmove smoothlyafter adjustment is
completed. Completelytighten the screwsholding the door hook
assemblyto the oven assembly.
3. Reconnect the short switch and check the continuityof the
monitor circuitand all latch switches againbyfollowing the
component test procedures.
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