Panasonic AR User Manual
ORDER NO. DCS-JUL2002-002-MS
Service Manual
Microwave Oven
NN-G61 AR
Specifications
Power Source:
Power requirement:
Output:
Microwave Frequency:
Timer:
Outside Dimensions:
Oven Cavity Dimensions:
Weight:
220 V AC, 50 Hz
Microwave:
Heater:
Microwave:
Heater:
Specifications subject to change without notice
1.450 W
860 W
900 W: Full Power (IEC 705-88)
800 W
2.450 MHz
99 min. 99 sec.
306 (W) x 555 (D) x 428 (H) mm
31 liters
Approx. 18 Kg
Panasonic do Brasil Ltda.
CS / DST - 2002
! WARNING
This service information is designed for experienced repair technicians only and is not designed for use by the general public. It
does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.
Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service
or repair the product or products dealt with in this service information by anyone else could result in serious injury or death.
! WARNING
1. This product should be serviced only by trained, qualified personnel.
2. Check for radiation leakage before and after every servicing according to the procedure for measuring radiation leakage.
3. If the unit cannot be repaired on site, advise the customer not to use until unit is repaired.
4. There are special components used in the microwave oven which are important for safety. These parts are marked with a on the
replacement parts list. It is essential that these critical parts should be replaced only with the manufactures specified parts to
prevent microwave leakage, shock, fire, or other hazards. Do not modify the orginal design.
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY
(A) Do not operate or allow the oven to be operated with the door open.
(B) Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source, and
make repairs as necessary:
(1) Interlock operation
(2) Proper door closing
(3) Seal and sealing surfaces (arcing, wear, and other damage)
(4) Damage to or loosening of hinges and latches.
(5) Evidence of dropping or abuse
(C) Before turning on microwave power for any service test or inspection within the microwave generating compartments, check
the magnetron, waveguide or transmission line, and cavity for proper alignment, integrity and connections.
(D) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave generation and trans-mission
systems shall be repaired, replaced, or adjusted by procedures described in this manual before the oven is released to the
owner.
(E) A microwave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven
prior to release to the owner.
CONTENTS
Safety Precautions ...................................................................................................................... 03
Procedure for Measuring Microwave Energy Leakage ................................................................ 04
Component Test Procedure ........................................................................................................ 05
Measurements and Adjustments ................................................................................................. 06
Electric Diagram .......................................................................................................................... 07
Schematic Diagram ..................................................................................................................... 08
Connections ................................................................................................................................. 10
Oven exploded view .................................................................................................................... 11
Cabinet exploded view ................................................................................................................ 12
Wiring Material ............................................................................................................................ 13
Cabinet Parts List ........................................................................................................................ 14
Door Assembly and Parts List .................................................................................................... 15
Escutcheon Assembly and Parts List .......................................................................................... 16
Electrical Parts List ..................................................................................................................... 17
Packing Parts List ....................................................................................................................... 18
Troubleshooting Guide ................................................................................................................. 19
SAFETY PRECAUTIONS
NN-G61 AR
CAUTIONS TO BE OBSERVED WHEN
TROUBLESHOOTING
Unlike many other appliances, the microwave oven is highvoltage, 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 magnetron.
Check the grounding
Do not operate on a 2-wire extension cord. The microwave
oven is designed to be used when grounded.
It is imperative, therefore, to make sure it is grounded properly before beginning repair work.
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, turn the oven off, wait
30 seconds and short the terminal of the high voltage capacitor (terminal of lead wire from diode) to chassis ground
with an insulated handle screwdriver or an insulated jumper
lead wire to discharge.
CONFIRM AFTER REPAIR
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.
1. Make sure that all electrical connections are tight before
inserting the plug into the wall outlet.
2. The special connection cable used for connection of this
apparate may be replaced only by qualified service-personnel using a special cable, which can be obtained only
from the Panasonic -Service. (Refer to Parts List).
Important Note
1. High voltage above 250V are existing on following parts
during operation.
Magnetron
High voltage transformer
High voltage Diode
High voltage Capacitor
Unusual attention should be paid during repair or
troubleshooting of product.
2. If the microwave oven is operated with incorrect installed
door hinge or magnetron, it can cause microwave leakage of over 5mW/cm2.
Hence it is absolutely necessary to check if magnetron
and door hinge are correctly and safely intalled after
repair or replacement.
WARNING
Never touch any circuit wiring your hand nor even with an
insulated tool during operation
When parts must be replaced, remove the power plug
from the outlet.
Avoid inserting nails, wire, etc. through any holes in
the unit during operation.
CAUTION
MICROWAVE RADIATION
Personnel should not be exposed to the microwave energy
which may radiate from the magnetron or other microwave
generating device it is improperly used or connected all
input and output microwave connection waveguides,
flanges, and gasket must be secure. Never operate the
device without a microwave energy absorbing load
attached. Never look into an open waveguide or antena
while the device is energized.
Never insert a wire, nail or any other metal objects 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 -
PROCEDURE FOR MEASURING MICROWAVE ENERGY LEAKAGE
Equipment
*Electromagnetic radiation monitor
*Glass thermometer 212°F or 100°F
*600cc glass beaker
Procedure for measuring radiation leakage
Note before measuring:
(1) Do not exceed meter full scale deflection. Leakage monitor
should initially be set to the highest scale.
(2) To prevent false readings the test probe should be held by
the grip portion of the handle only and moved along the shaded
area shown in Figure no faster than 1 inch/sec (2.5 cm/sec)
(3) Leakage with the outer panel removed less than 5mW/cm2
(4) Leakage for a fully assembled oven with door normally closed
less than 2mW/cm2.
(5 ) Leakage for a fully assembled oven [Before the latch switch (primary)
is interrupted] while pulling the door less than 2mW/cm2
1. Pour 275±15cc (9ozs± 1/2oz) of 20± 5°C(68± 9°F) water
in a beaker which is graduated to 600cc, and place the
beaker in the center of the oven.
2. Set the radiation monitor to 2450MHz and use it following
the manufactuers recommended test procedure to assure
correct results.
3. When measuring the leakage, always use the 2 inch (5cm)
spacer supplied with the probe.3.
4. Tap the start pad or set the timer and with the magnetron
oscillating, measure the leakage by holding the probe
perpendicular to the surface being measured.
(2) Measurements with a fully assembled oven.
After all components, including the outer panel are fully
assembled, measure for radiation leakage around the door
periphery, the door viewing window, the exhaust opening and air
inlet openings.
(1) Measurement with the outer panel removed.
Whenever you replace the magnetron, measure for radiation
leakage before the outer panel is installed and after all necessary
components are replaced or adjusted. Special care should be
taken in measuring around the magnetron.
- 4 -
COMPONENT TEST PROCEDURE
NN-G61 AR
CAUTION
1. High voltage is present at the high voltage terminal of
the high voltage transformer during any cook cycle.
2. It is neither necessary nor advisable to attempt
measurement of the high voltage.
3. Before touching any oven components or wiring, always
unplug the oven from its power source and discharge
the high voltage capacitor.
High voltage transformer
1. Remove connections from the transformer terminals and check
continuity.
2. Normal (cold) resistance readings should be as follows:
Secondary winding Approx. 80Ω; ~ 120Ω;
Filament winding Approx. 0Ω;
Primary winding (0v ~ 230/240V) Approx. 0Ω; ~ 3Ω;
Diode
1. Isolate the diode assembly from the circuit by disconnecting
the leads.
2. With the ohmmeter set on the highest resistance scale,
measure the resistance across the diode terminals. Reverse
the meter leads and again observe the resistance reading.
Meter with 6V, 9V or higher voltage batteries should be used
to check the front-to-back resistance of the diode, otherwise
an infinite resistance may be read in both directions. A normal
diodes resistance will be infinite in one direction and several
hundred KΩ; in the order direction.
Magnetron
Continuity checks can only indicate an open filament or a shorted
magnetron. To diagnose for an open filament or shorted
magnetron.
1. Isolate magnetron from the circuit by disconnecting the leads.
2. A continuity check across magnetron filament terminals should
indicate one ohm or less.
3. A continuity check between each filament terminal and
magnetron case should read open.
High voltage capacitor
2. Check continuity of capacitor with ohmmeter on highest ohm scale.
2. A normal capacitor will show continuity for a short time, and
then indicate 9MΩ; once the capacitor is charged.
3. A shorted capacitor will show continuous continuity.
4. An open capacitor will show constant 9MΩ;.
(Due to internal 9MΩ; resistor)
5. Resistance between each terminal and chassis should be infinite.
Membrane key board (Membrane switch assembly)
Check continuity between switch terminals, by pressing an
appropriate pad on the key board.
The contacts assignment of the respective pads on the key board
is as shown in the schematic diagram.
Protector diode
1. Isolate the protector diode assembly from the circuit by
disconnecting its leads.
2. With the ohmmeter set on the highest resistance scale,
measure the resistance across the protector diode terminals.
Reverse the meter leads and again observe the resistance
reading. A normal protector diodes resistance will be infinite in
both directions. It is faulty if it shows continuity in one or both
directions.
- 5 -
MEASUREMENTS AND ADJUSTMENTS
Adjustment of Primary latch switch, Secondary latch switch
and short switch
1. When mounting Primary latch switch, Secondary latch switch
and short switch to door hook assembly, mount the Primary
latch switch, the Secondary latch switch and the short switch
to the door hook assembly as shown in Figure.
NOTE: No specific adjustment during installation of Primary
latch switch, Secondary latch switch and short switch
to the door hook is necessary.
2. When mounting the door hook assembly to the oven assembly,
adjust the door hook assembly by moving it in the direction of
arrow in Figure so that the oven door will not have any play in
it. Check for play in the door by pulling the door assembly.
Make sure that the latch keys move smoothly after adjustment
is completed. Completely tighten the screws holding the door
hook assembly to the oven assembly.
Measurement of microwave output
The output power of the magnetron can be determined by
performing IEC standard test procedures.
However, it is possible to test the magnetron by following
procedure outlined below.
Necessary equipment:
*1 liter beaker *Glass thermometer
*Wrist watch or stopwatch
NOTE: Check the line voltage under load to ensure it meets
specifications. Low voltage condition will cause a reduction
in magnetron output. Temperature readings and heating
time, should be as accurate as possible.
Output power performance test procedure.
1. Fill the beaker with exactly one litre of tap water. Stir the water
using the thermometer and note the temperature. (Record as T1)
2. Place the beaker in the center of cook plate. Set the oven for
High power and heat for exactly one minute.
3. After completion of the heating cycle, stir the water again with
the thermometer and note the temperature. (Record as T2)
The normal temperature rise (T2-T1), for these models should
be more than 7.0°C using the High power
selection with the oven operating at the specified line voltage.
Please confirm that the gap between the switch housing and
switch actuator lever is no more than 1.0mm when the door
is closed.
- 6 -
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