Panasonic NN-ST652W Schematic

Order No. MOD1006319 PE

Microwave Oven

Model No.

32L

White

Brazil

NN-ST652WRUN

NN-ST652WRUK

s

Power Requirement

Power Output

Microwave Frequency

Magnetron

Timer

Outside Dimensions

Internal Capacity

Weight

NN-ST652WRUN

127

VoltsAC60Hz

1,650 Watts (14.0 A)

Single phase, 3 wire grounded

900 Watts full microwave power (IEC60705)

2,450 MHz

2M219J

0 ~ 99 minutes and 50 seconds

520 325

(W) x (H)x416(D) mm

32 Litros

14.2kg (approx.)

Specifications subject to change without notice.

220

1,650 Watts (8.0 A)

Single phase, 3 wire grounded

© Panasonic Corporation 2012 Unauthorized
copying and distribution is a violation of law

NN-ST652WRUK

VoltsAC60Hz



Thisproductshouldbeservicedonlybytrainedqualifiedpersonnel.

Thisservicemanualcoversproductsforfollowingmarkets.

Whentroubleshootingorreplacingparts,pleaserefertothecountryidentificationsshownbelowforyour

applicableproductspecification.

WARNING 

SAFETY PRECAUTIONS

This device is to be serviced only by properly qualified service personnel.
Consult the service manual for proper service procedures to assure continued safety operation and for precautions to be
taken to avoid possible exposure to excessive microwave energy.

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, wave guide 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 transmission 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.

CAUTION

MICROWAVE RADIATION

DO NOT BECOME EXPOSED TO RADIATION FROM THE MICROWAVE GENERATOR
OR OTHER PARTS CONDUCTING MICROWAVE ENERGY.

CONTENTS

(Page)

SAFETY PRECAUTIONS

SPECIFICATIONS

CAUTIONS

INSTALLATIONS

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OPERATING INSTRUCTIONS

FEATURES

CONTROL PANEL

OPERATING SEQUENCE

SCHEMATIC DIAGRAM

CIRCUIT DESCRIPTION

-----------------------------------------------------------------------------------------------------------------------

SERVICE INFORMATION

TOOLS AND MEASURING INSTRUMENTS

MICROWAVE LEAKAGE TEST

MEASUREMENT OF MICROWAVE POWER OUTPUT

DISASSEMBLY AND ADJUSTMENT

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Inside front cover

1-1

2-1

3-1

4-1

4-1

4-1

4-2

4-3

4-4

5-1

5-1

5-1

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5-3

5-3

INTERLOCK CONTINUITY TEST

COMPONENT TEST PROCEDURE

TROUBLE SHOOTING

EXPLODED VIEW

REPLACEMENT PARTS LIST

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SC HEM ATI C DIA GR AM O F P. C. B

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5-7

5-8

5-12

6-1

7-1

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8-1

POWER LEVEL & ACCESSORIES

ITEM

Control Complement

Rating Label Location

Accessories

This microwave oven is designed for household use only.

Microwave Power for Variable Cooking

Power level

Max

Medium High

Medium

Medium Low

I

Low

Instruction manual
Glass Tray
Ro Rller ing

900 Watts
720 Watts

540 Watts
270 Watts

90 Watts

Inside

DESCRIPTION

It is not recommended for commercial purposes.

1-1

• DO NOT operate on a 2-wire extension cord during
repair and use.

• NEVER TOUCH any oven components or wiring during
operation.

• BEFORE TOUCHING any parts of the oven, always
remove the power plug from the outlet.

• For about 30 seconds after the oven stops, an electric
charge remains in the high voltage capacitor. When
replacing or checking, you must discharge the high
voltage capacitor by shorting across the two terminals
with an insulated screwdriver.

•

Remove your watches whenever working close to or

replacing the Magnetron.

• NEVER operate the oven with no load.

• NEVER injure the door seal and front plate of the oven
cavity.

• NEVER put iron tools on the magnetron.

• NEVER put anything into the latch hole and the
interlock switches area.

• Proper operation of the microwave oven requires that
the magnetron be assembled to the waveguide and
cavity. Never operate the magnetron unless it is
properly installed.

• Be sure that the magnetron gasket is properly
installed around the dome of the tube whenever
installing the magnetron.

2-1

CAUTIONS

Unlike other appliances, the microwave oven is
high-voltage and high-current equipment.
Though it is free from danger in ordinary use,
extreme care should be taken during repair.

THE OVEN IS TO BE SERVICED ONLY
BY PROPERLY QUALIFIED SERVICE
PERSONNEL.

MICROWAVE RADIATION

Personnel should not be exposed to the
microwave energy which may radiate from the
magnetron or other microwave generating
device if it is improperly used or connection.
All input and output microwave connections,
waveguide, flange and gasket must be secure
never operate the device without a microwave
energy absorbing load attached.
Never look into an open waveguide or antenna
while the device is energized.

ANTENNA

COOLING FIN

MAGNETRON
CHASSIS GROUND

FILAMENT
TERMINALS

MAGNETRON

GASKET

INSTALLATIONS

BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY.

INSTALLING

1. Empty the microwave oven and clean inside it with
a soft, damp cloth. Check for damage such as
misaligned door, damage around the door or dents
inside the cavity or on the exterior.

2. Put the oven on a counter, table, or shelf that is
strong enough to hold the oven and the food and
utensils you put in it. (The control panel side of the
oven is the heavy side. Use care when handling.)

3. Do not block the vent and the air intake openings.
Blocking vent or air intake openings can cause
damage to the oven and poor cooking results.
Make sure the microwave oven legs are in place to
ensure proper air flow.

4. The oven should not be installed in any area where
heat and steam are generated, because they may
damage the electronic or mechanical parts of the
unit.
Do not install the oven next to a conventional
surface unit or above a conventional wall oven.

5. Use microwave oven in an ambient temperature
less than 104°F(40°C).

6. Place the microwave oven on a sturdy and flat
surface at least 10 cm(4 inches) from the wall.

7. Place the microwave oven as far away as possible
from TV, RADIO, COMPUTER, etc., to prevent
interference.

EARTHING INSTRUCTIONS

This microwave oven is designed to be used in a fully
earthed condition.
It is imperative, therefore, to make sure it is properly
earthed before servicing

WARNING­THIS APPLIANCE
MUST BE EARTHED

IMPORTANT

The wires in this mains lead are colored in
accordance with the following code:

Green-and-yellow: Earth
Blue: Neutral
Brown: Live

As the colors of the wires in the mains lead of this
appliance may not correspond with the colored
markings identifying the terminals in your plug,
proceed as follows.

The wire which is colored green-and-yellow must be
connected to the terminal in the plug which is marked
with the letter E or by the earth symbol ( ) or
colored green or green-and-yellow.

10cm

The wire which is colored blue must be connected to
the terminal in the plug which is marked with the letter
N or colored black.

The wire which is colored brown must be connected
to the terminal in the plug which is marked with the
letter L or colored red.

3-1

OPERATING INSTRUCTIONS

FEATURES

See-Through oven window

CONTROL PANEL

Door C

Oven Front Plate

Control Panel

Safety Door Lock System

Glass Tray

Roller Ring

(1)

(2)

(3)

(4)

(7)

(9)

(8)

(5)
(6)

-

NN-

ST652W

(1)

Display

(2)

Power Selection Tab
Number Tabs

(3)

Memory Tab

(4)

Timer / Clock Tab

(5)

+ 30 sec. Tab

(6)

Auto Cook Options

(7)

Defrost Tab

(8)

Serving / Weight Tab

(9)

Stop / Cancel Tab

(10)

Before Cooking:
During Cooking:

process. Another tap cancels

Start Tab

(11)

One tap begins oven

Beep Sound:

When a pad is pressed correctly, a beep will be heard.
If a pad is pressed and no beep is heard, the unit did
not or cannot accept the instruction. The oven will beep
twice between

complete program, the oven will beep 5 times.

R

UN

one tap cancels
one tap

functioning.

programmed stages. At the end of any

ST652W

NN

/

the inserted instructions.

temporarily stops the cooking

cooking.

R

UK

(10)

(11)

4-1

OPERATING SEQUENCE

The following is a description of component functions
during oven operation.

1. SETTING THE CLOCK

Stop/

Cancel

NOTE: This is a 12 hour clock.

Clock

Set the time

by pressing
time pads

Clock

2. CANCEL FUNCTION

Touch the S /Cancel pad whenever you need to

cancel an entry or a function currently in use.
The display will either return to the last item entered
or to the clock.

top

3. MICROWAVE COOKING

Stop/Cancel

TIME START

4. AUTO DEFROST COOKING

Stop/

Cancel

Desired

defrost

program

Desired
weight

Start

5. CHILD SAFETY LOCK

Using this system will make the oven inoperable; however,

the door can be opened.Child Lock can be set when the

display shows a colon or the time.

TO Set

Start

Press Start Pad 3 consecutive times.

The display will the indication on the word LOCK.

It indicates no programming will be accepted.

To Cancel

Stop/ Cancel

Press Stop/ Pad 3 consecutive times.
The colon or the time will be displayed again on the display.
In case of plug disconnection or energy shortage,the
lock will be automatically canceled.

Reset

4-2

SCHEMATIC DIAGRAM

4-3

CIRCUIT DESCRIPTION

GENERAL DETAILS

• The low voltage transformer supplies the necessary
voltage to the micom controller when power cord is
plugged in.

• When the door is closed, the primary switch is ON, the

secondary switch is ON, and the monitor switch opens
(contact COM and NO).

WHEN SELECTING COOKING POWER
LEVEL AND TIME

• The micom controller memorizes the function you set.

• The time you set appears in the display window.

• Each indicator light turns on to indicate that the stage

has been set.

WHEN TOUCHING THE START PAD

• The coil of the relay is energized by the micom

controller.

• Power input is supplied to the high voltage transformer

through the fuse to the primary switch and relay 2.

• Turntable rotates.

FUSE

L

N

MICOM CONTROLLER

PRIMARY

SWITCH

RELAY 2

MONITOR

SWITCH

TRANS-

FORMER

SECONDARY
SWITCH

power of microwave oven as POWER LEVEL.

(refer to page 1-1)

WHEN THE DOOR IS OPENED DURING
COOKING

• Both the primary switch and relay 2 are cut off primary
winding voltage of the high voltage transformer.

• ON-OFF of relay 2 is coupled electrically with opening
and closing of the secondary switch.

• When the door is opened, the secondary switch is
opened and when the door is closed, the secondary
switch is closed.

• The cooking time stops counting down.

• Relay stops functioning.

• As the door is opened, if the contact of primary switch
and relay 2 and/or secondary switch fails to open, the
fuse opens due to the large current surge caused by
the monitor switch activation, which in turn stops
magnetron oscillation.

FUSE

L

N

MICOM CONTROLLER

PRIMARY

SWITCH

RELAY 2

MONITOR

SWITCH

FORMER

SECONDARY
SWITCH

• The fan motor rotates and cools the magnetron by
blowing the air (coming from the intake on the
backplate).

• The air is also directed into the oven to exhaust the
vapor in the oven through the left side.

• Cooking time starts counting down.

• 3.2 volts AC is generated from the filament winding of
the high voltage transformer. This 3.2 volts is applied to
the magnetron to heat the magnetron filament through
two noise-preventing choke coils.

• A high voltage of approximately 2100 volts AC is
generated in the secondary of the high voltage
transformer which is increased by the action of the high
voltage diode and charging of the high voltage
capacitor.

• The negative 4000 Volts DC is applied to the filament
of the magnetron.

WHEN THE OVEN IS SET AT ANY LEVEL
EXCEPT MAXIMUM.

• The micom controller controls the ON-OFF time of relay
2 by the applied signal to vary the average output

4-4

CAUTIONS

• Be sure to check microwave leakage prior to
servicing the oven if the oven is operative prior to
servicing.

• The service personnel should inform the
manufacture importer, or assembler of any
certified oven unit found to have a microwave
emission level in excess of 5 mW/cm

2

and should
repair any unit found to have excessive emission levels
at no cost to the owner and should ascertain the cause
of the excessive leakage. The service personnel
should instruct the owner not to use the unit until the
oven has been brought into compliance.

• If the oven operates with the door open, the service
personnel should:

- Tell the user not to operate the oven.

- Contact the manufacturer.

• The service personnel should check all surface and
vent openings for microwave leakage.

• Check for microwave leakage after every servicing.
The power density of the microwave radiation leakage
emitted by the microwave oven should not exceed
4 mW/cm

2

. Always start measuring of an unknown field
to assure safety for operating personnel from radiation
leakage.

MEASURING MICROWAVE ENERGY
LEAKAGE

• Pour 275±15cc of 20±5°C(68±9°F) water in a beaker
which is graduated to 600 cc, and place the beaker
on the center of the turntable.

• Set the energy leakage monitor to 2450 MHz and
use it following the manufacturer's recommended
test procedure to assure correct result.

• When measuring the leakage, always use the 2­inch (5cm) spacer supplied with the probe.

• Operate the oven at its maximum output.

• Measure the microwave radiation using and
electromagnetic radiation monitor by holding the
probe perpendicular to the surface being measured

Move probe along shaded area

Probe scanning speed
Less than 2.5 cm/sec
( 1in/sec)

5-1

SERVICE INFORMATION

TOOLS AND MEASURING INSTRUMENTS

MICROWAVE LEAKAGE TEST

NECESSARY TOOLS

Tools normally used for TV servicing are sufficient.
Standard tools are listed below.

• Diagonal pliers

• Long nose pliers

• Phillips screwdriver

• Flat blade screwdriver

• Wrench (size 5mm)

• Nutdriver (size 5mm)

• Adjustable wrench

• Soldering iron

• Solder

• Vinyl insulation tape

• Polishing cloth

NECESSARY MEASURING INSTRUMENTS

• TESTER(VOLTS-DC, AC., Ohmmeter)

• Microwave survey meter

- Holaday HI-1500
HI-1501

- Narda 8100

8200

• Inch scale

• 600 cc non conductive material beaker (glass or plastic),
inside diameter: approx. 8.5 cm(3

1

/2

in.)

• Cylindrical and made of borosilicate glass vessel.
max. thickness: 3 mm
outside diameter: approx. 190mm
height: approx. 90mm

• Glass thermometer: 100°C or 212°F (1 deg scale)

MEASUREMENT WITH OUTER CASE
REMOVED

• When you replace the magnetron, measure for
microwave energy leakage before the outer case is
installed and after all necessary components are
replaced or adjusted.
Special care should be taken in measuring the
following parts. (Circled area of below Fig.)

- Around the magnetron

- The waveguide

WARNING : AVOID CONTACTING ANY

HIGH VOLTAGE PARTS

NOTES WHEN MEASURING

• Do not exceed meter full scale deflection.

• The test probe must be removed no faster than

1 inch/sec (2.5 cm/sec) along the shaded area,
otherwise a false reading may result.

• The test probe must be held with the grip portion of the
handle.

A false reading may result if the operator's hand is

between the handle and the probe.

• When testing near a corner of the door, keep the probe
perpendicular to the surface making sure the probe
horizontally along the oven surface, this may possibly
cause probe damage.

RECORD KEEPING AND NOTIFICATION
AFTER MEASUREMENT

• After adjustment and repair of any microwave energy
interruption or microwave energy blocking device,
record the measured values for future reference. Also
enter the information on the service invoice.

• The microwave energy leakage should not be more
than 4 mW/cm2.sq. after determining that all parts are
in good condition, functioning properly and genuine
replacement parts which are listed in this manual have
been used.

• At least once a year, have the electromagnetic energy
leakage monitor checked for calibration by its
manufacturer.

MEASUREMENT WITH A FULLY
ASSEMBLED OVEN

• After all components, including the outer case, are fully
assembled, measure for microwave energy leakage
around the door viewing window, the exhaust opening,
and air inlet openings.

• Microwave energy leakage must not exceed the values
prescribed below.

NOTE: Leakage with the outer case removedless than

5 mW/cm2.sq. Leakage for a fully assembled
oven (Before the latch switch (primary) is
interrupted) with the door in a slightly opened
position-less than 2 mW/cm2.sq.

5-2