LG MC-805GLR User manual

MICROWAVE/GRILL
CONVECTION OVEN
SERVICE MANUAL
MODEL
:
MC-805GLR
CAUTION
BEFORE SERVICING
THE
UNIT,
READ THE
SAFETY PRECAUTIONS
IN
THIS MANUAL.

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.
SAFETY PRECAUTIONS
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 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.

TABLE
OF CONTENTS
(Page)
SAFETY PRECAUTIONS
.................................................................................................
Inside front cover
SPECIFICATIONS
......................................................................................................................................1-1
CAUTIONS
................................................................................................................................................ 2-1
INSTALLATIONS
.......................................................................................................................................
3-1
OPERATING INSTRUCTIONS
.................................................................................................................. 4-1
FEATURES
........................................................................................................................................... 4-1
CONTROL
PANEL .................................................................................................................................4-1
OPERATING
SEQUENCE
.................................................................................................................... 4-2
SCHEMATIC DIAGRAM
.......................................................................................................................
4-3
CIRCUIT DESCRIPTION
...................................................................................................................... 4-4
SERVICE INFORMATION
.........................................................................................................................
5-1
TOOLS
AND
MEASURING INSTRUMENTS
........................................................................................
5-1
MICROWAVE LEAKAGE TEST
............................................................................................................
5-1
MEASUREMENT OF MICROWAVE POWER OUTPUT
.......................................................................
5-3
DISASSEMBLY
AND
ADJUSTMENT .....................................................................................................5-3
INTERLOCK CONTINUITY TEST
........................................................................................................
5-8
COMPONENT TEST PROCEDURE
.....................................................................................................
5-9
TROUBLE SHOOTING GUIDE
...........................................................................................................
5-14
EXPLODED
VIEW .....................................................................................................................................
6-1
REPLACEMENT PARTS LIST
.................................................................................................................. 7-1
SCHEMATIC DIAGRAM OF P.C.B.
...........................................................................................................
8-1
PRINTED
CIRCUIT BOARD................................................................................................................. 8-2
PCB PARTS LIST....................................................................................................................................... 9-1

SPECIFICATIONS
1-1
ITEM
DESCRIPTION
Power
Requirement
230/240V AC50Hz
Single
phase,
3 wire
grounded
Microwave 1350W
Grill 1350W
Convection 1450W
Combination 1450W
Power
Output
850W full microwave
power(IEC705)
Microwave
Frequency
2,450MHz
Magnetron
2M214
-
39F,
2M218J
Timer 99min. 50sec.
Outside
Dimensions
530(W)
X
322
X
500mm
Cavity
Dimensions
348(W)
X
232
X
374mm
Net
Weight 23.0kg
Shipping weight 25.5kg
Control
Complement
Microwave Power for Variable
Cooking
Power level
HIGH...............................................Full
power
throughout
the
cooking
time(100%)
MED-HIGH
.....................................approx.
80% of Full
power
MEDIUM
.........................................approx.
60% of Full
power
DEFROST
......................................approx.
40% of Full
power
LOW
...............................................approx.
20% of Full
power
?
Convection
-
Max. 250°C
?
Grill
?
Combination
Name
plate
Location
Accessories
Owner's
manual Glass
tray
Rotating ring
Convection rack
Grill rack Metal
tray
Rotisserie-Bar
Rotisserie-Handle
This microwave oven is
designed
for household use
only.
It
is not recommended for commercial
purpose.
Back Side

?
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
stop,
an electric
charge
remains on the
high voltage
capacitor.
When
replacing
or
checking,
you
must
discharge
the
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
damage
the door seal or 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
appliance.
Though
it
is free from
danger
in
ordinary
use,
extreme care should be taken
during
repair.
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 connected.
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
GASKET
FILAMENT
TERMINAL
COOLING
FIN
MAGNETRON
CHASSIS
GROUND
THE
OVEN IS TO
BE
SERVICED ONLY
BY
PROPERLY
QUALIFIED
SERVICE
PERSONNEL.
MAGNETRON

Installing
microwave oven
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,
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 the microwave oven
in
an ambient
temperature
of less than 104°F
(40°C).
6. Place the microwave oven on a
sturdy
and flat
surface,
at least
10cm(4 inches)
from the wall.
7.
Place the microwave oven as far
away
as
possible
from
TV, RADIO,
COMPUTER
etc,
to
prevent
interference.
8. This oven must be
plugged
into a 15A outlet.
9. Do not touch the front
glass during
or after
cooking
of the
Grill,
Convection and Combination mode.
This
glass
is
very
hot
during
heater
operating.
10. Do not
operate
oven at microwave and combination
mode
with
the Convection rack or Grill rack
placed
in
the
cavity
when the oven is
empty.
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.
WARNING-
THIS APPLIANCE
MUST
BE EARTHED
IMPORTANT
As the colours of the wires
in
the mains lead of this
appliance
may
not
correspond
with
the coloured
markings identifying
the terminals
in
your
plug,
proceed
as follows.
The wire which is coloured
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 coloured
green
or
green-and yellow.
The wire which is coloured
blue
must be connected to
the terminal
in
the
plug
which is marked
with
the letter
N
or coloured
black.
The wire which is coloured
brown
must be connected to
the terminal
in
the
plug
which is marked
with
the letter
L
or coloured
red.
*
Power cord
type:
"Y"
Type
3-1
INSTALLATIONS
BEFORE YOU
BEGIN,
READ THE
FOLLOWING INSTRUCTIONS COMPLETELY
AND
CAREFULLY.
The wires
in
this mains lead are coloured
in
accordance
with
the
following
code:
Green-and-yellow:
Earth
Blue: Neutral
Brown: Live

OPERATING INSTRUCTIONS
4-1
1.
Grill: To select
grill cooking.
2.
MICRO POWER:
To select micro
power
cooking
and
cooking
power
levels.
3.
AUTO COOK:
To select auto cook.
4.
CLOCK:
To set the time of
day.
5.
AUTO ROAST
6.
TIME:
To set
cooking
times.
7.
DISPLAY WINDOW:
Used to show Time of
day,
Cooking
of
day,
Cooking
power
level,
Cooking
category.
8.
COMBINATION:
To select combination
cooking.
9.
CONVECTION:
To select convection
cooking.
10.
AUTO
WEIGHT
DEFROST:
To select auto
weight
defrost.
11.
WEIGHT: To set
weight
of food auto
weight
defrost.
12.
LESS/MORE:
To select convection
temperature,
and
change
auto cook time and auto reheat time.
13.
STOP/CLEAR,
CHILD
LOCK:
Stops
the oven and
clear all entries
except
the time of
day.
14.
START/QUICK
START:
To
quickly
set the
cooking
time
directly.
Control
panel
Glass turntable
Rotating ring
Shaft
Metal
tray
Convection rack Grill rack
Oven front face
Window door screen
Door seal
Latch
ROTISSERIE-BAR
ROTISSERIE-HANDLE
2
8
9
10
11
12
13
14
7
1
4
5
6
3
10min1min 10sec
Stop/Clear
Quick
Star
1. Meat
2. Poultr
1. Jacket Potato
2. Rice/Pasta
1. Roast Beef
2. Roast Pork
3.
Whole
Chicken
3. Fresh
Vegetables
2. Frozen
Vegetables
1. Fish
2. Bread
Auto Cook
Micro Grill Conv Combi
0.1kg 1.0kg
More
Features
Control Panel

The
following
is a
description
of
component
functions
during
oven
operation.
1.
Setting
the clock
2.
Cooking(Microwave
power)
3. Multi
stage cooking
4.
Grill
cooking
5. Convection
cooking
To
pre-heat
To cook
6. Combination
cooking
7.
Auto
weight
defrost
8. Auto roast
9. Auto cook
10. Child lock
This oven has a CHILD
LOCK
feature.
To Set CHILD LOCK
To Cancel CHILD LOCK
11.
Quick
start
12.
More and Less
Operating Sequence
4-2
Plug
the
power
cord into an
electric outlet
Clock
Set
the
correct
minute
Clock
Set
the
correct hour
Stop
Stop
Desired
power
level
Desired
cooking
time
Start
Stop
Desired
power
level
Desired
cooking
time
Desired
cooking
time
Start
Stop Stop
(Touch
and
HOLD)
Stop Stop
(Touch
and
HOLD)
Stop
Start
Stop
More
Less
Programme
desired auto cook
Stop
Desired
defrost
category
Desired
cooking
weight
Start
Stop
Desired
auto roast
category
Desired
cooking
weight
Start
Stop
Desired
auto cook
category
Desired
cooking
weight
Start
Desired
power
level
(20%,
40% or
60%)
Desired
cooking
time
Start
Stop
Desired convection
temp(40oC,
100oC~250oC)
Start
Stop
Desired convection
temp
(40oC, 100oC~250oC)
Start
Combination
Desired convection
temp(100oC~250oC)
Grill
Desired
power
level
Desired
power
level
Desired
cooking
time
Start
Desired
cooking
time
Grill or
convection or
combination
Desired
cooking
time
Stage
1
OR
Stage
2

SCHEMATIC DIAGRAM
4-3

?
As the door is
closed,
the contact of
MONITOR
SWITCH
opens.
This switch creates the short circuit to
blow 10
A
fuse
during
operation
under abnormal
condition.(ie,
should the contacts of
primary
fail to
open
the
circuit)
?
The latches are secured
by
latch board. The oven
light
turns on while the oven is
in
operation.
WHEN
COOKING POWER
LEVEL AND
COOKING
TIME ARE
SET
?
The contacts of the
primary
switch and the
secondary
switch close the circuit.
?
230V A.C. is
applied
to the
high voltage
transformer
through
power
control switch as shown
by
the solid
line.
?
Turntable and circulation motor rotate.
?
The fan motor rotates and cools the
magnetron
by
blowing
the air
(coming
from the intake on the
backplate)
over the
magnetron.
?
The air is also directed into the oven to exhaust the
vapor
in
the oven
through
the base
plate
and back
plate.
?
3.5V A.C. is
generated
from the filament
winding
of the
high voltage
transformer. This 3.5V is
applied
to the
magnetron
to heat the
magnetron
filament
through
two
noise
preventing
choke coils.
A
high voltage
of
approximately
2100V A.C. is
generated
in
the
secondary
of the
high voltage
transformer which is
increased
by
the action of the diode and
charging
of
the
high voltage
capacitor.
The
negative
D.C.
voltage
is
then
applied
to the filament of the
magnetron.
WHEN THE
DOOR IS OPEN DURING
COOKING
?
Both
primary
switch and
secondary
switch
open
to cut
off the
primary
winding voltage
to the
high voltage
transformer to
stop
microwave oscillation.
?
Turntable and fan motor
stop.
?
As the door is
opened,
if
the contact of
primary
switch
and
relay
2
and/or
secondary
switch fail to
open,
the
10A fuse
opens
due to the
large
current
surge
caused
by
the monitor switch activation which
in
turn
stops
magnetron,
oscillation.
WHEN
TOUCHING
THE
START
KEY
WITH THE
CONVECTION/GRILL
COOKING FUNCTION SELECTED.
?
The contacts of the
primary
switch and the
secondary
switch close the circuit.
?
230V A.C. is
applied
to the
grill
heater
through grill
thermostat as shown
by
the solid line.
?
Turntable rotate.
?
The fan motor and circulation motor rotate.
?
The air is also directed into the oven to exhaust the
vapor
in
the oven
through
the base
plate
and back
plate.
Circuit
Description
4-4
FUSE
10A
PRIMARY
SWITCH
N
L
RELAY 2
H.V.T
MONITOR
SWITCH
FUSE
10A
PRIMARY
SWITCH
N
L
RELAY 2
H.V.T
MONITOR
SWITCH
CONVECTION
HEATER
RELAY 4
L
N
E
N
L
G-Y
RELAY
3
GRILL
HEATER
OVEN THERMOSTAT
L
N
E
N
L
G-Y
RELAY
3
GRILL
HEATER
OVEN THERMOSTAT

NECESSARY TOOLS
Tools
normally
used for
TV
servicing
are sufficient.
Standard
tools are listed below.
?
Diagonal
pliers
?
Long
nose
pliers
?
Cross head screwdriver
?
Wrench
(size
5
mm)
?
Nutdriver
(size
5
mm)
?
Adjustable
wrench
?
Soldering
iron
?
Solder
?
Vinyl
insulation
tape
?
Polishing
cloth
CAUTIONS
?
Be sure to check a microwave emission
prior
to
servicing
the oven
if
the oven is
operative prior
to
servicing.
?
If
the oven
operates
with
door
open,
the service
personnel
should;
---Tell the user not to
operate
the oven
?
The service
personnel
should check all surface and
vent
openings
for microwave emission
testing.
?
Check for microwave
energy leakage
after
every
servicing.
The
power
density
of the microwave
radiation
leakage
emitted
by
the microwave oven
should not exceed
4
mW/cm2.
And
always
start
measuring
of an unknown field to
assure
safety
for
operating
personnel
from radiation
leakage.
NOTE:
The standard is 5 mW/cm2 while
in
the
customer's home.
4
mW/cm2 stated here is
manufacturer's own
voluntary
standard for units
in
customer's home.
EQUIPMENT
?
Microwave
Survey
Meter
?
600cc
glass
beaker
?
Glass thermometer 100°C
NECESSARY MEASURING
INSTRUMENTS
?
TESTER
(VOLTS-DC,
AC,
Multmeter)
?
Microwave
survey
meter
---Holaday
H1-1500,
Hi-1501
---Narda
8100,
8200
?
Inch scale
?
600 cc non conductive material beaker
(glass
or
plastic),
inside diameter:
approx.
8.5cm
(31/2 in.)
?
Cylindrical
and made of borosilicate
glass
vessel max.
thickness: 3mm
outside diameter:
approx.
190mm
height:
approx.
90mm
?
Glass thermometer: 100°C or
212°F
(1
deg
scale)
MEASURING MICROWAVE ENERGY
LEAKAGE
?
Pour 275
±
15cc of 20°C
±
5°C 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
2,450
MHz
and use
it
following
the manufacturer's recommended test
procedure
to assure correct result.
?
When
measuring
the
leakage,
always
use the
2
inch
(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.
Tools and
Measuring
Instruments
5-1
Microwave
Leakage
Test
SERVICE INFORMATION
Move
probe
along
shaded area.
Probe
scanning
speed;
Less than 2.5 cm/sec

MEASUREMENT
WITH THE
OUTER
CASE REMOVED
?
When
you
replace
the
magnetron,
measure microwave
energy leakage
before the out case is installed and
after all
necessary
components
are
replaced
or
adjusted.
Special
care should be taken
in
measuring
the
following
parts. (Shaded
area of below
Fig.)
---
Around the
magnetron
---
The
waveguide
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.
NOTES:
Leakage
with
the outer case removed
-
less than
5 mW/cm2.
Leakage
for a
fully
assembled oven
("Before
the latch
switch
(primary)
is
interrupted")
with
the door
in
a
slightly
opened position
-
less than
4
mW/cm2.
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.
?
Should
the microwave
energy leakage
not be more
than
4
mW/cm2 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
manufacture.
5-2
WARNING: AVOID CONTACTING
ANY
HIGH VOLTAGE PARTS

?
Microwave
power output
measurement is made
with
the microwave oven
supplied
at its rated
voltage
and
operated
at its maximum microwave
power
setting
with
a load of
(1000
±
5)g
potable
water.
?
The water is contained
in
a
cylindrical
borosilicate
glass
vessel
having
a maximum material thickness of
3
mm
and an outside diameter of
approximately
190
mm.
?
The oven and the
empty
vessel are at ambient
temperature prior
to the start of the test.
?
The initial
temperature (±1)
of the water is
(10±2)°C.
It
is measured
immediately
before the water is added to
the vessel. After addition of the water to the
vessel,
the
load is
immediately
placed
on the center of the shelf
which is
in
the lowest
position
and the microwave
power
switched on.
?
The time
T
for the
temperature
of the water to rise
by
a
value
!T
of
(10±2)°K
is
measured,
where
T
is the time
in
seconds and
!T
is the
temperature
rise. The initial
and final water
temperatures
are selected so that the
maximum difference between the final water
temperature
and the ambient
temperature
is 5°K.
A.
OUT CASE REMOVAL
1)
Disconnect
power
supply
cord from the outlet.
2)
Remove the screws from the rear and side section.
The out case must be moved backward to the lifted off.
B.
POWER SUPPLY CORD
1)
Remove the out case.
2)
Disconnect two terminals from the noise filter
assy
and remove one screw of the earth terminal.
CAUTION: DISCHARGE
HIGH
VOLTAGE
CAPACITOR BEFORE SERVICING
(refer
to
page
5)
C. REMOVING CONTROL
PANEL
ASSEMBLY
AND
PCB ASSEMBLY
1)
Disconnect the leadwire from the PCB
SUB ASM.
2)
Remove the screws for the earth and
securing
the
control
panel.
3)
Lift
control
panel
assembly
from the oven
by
the tab
unhooked.
?
The microwave
power output
P in
watts is calculated
from the
following
formula:
P=
is measured while the microwave
generator
is
operating
at full
power.
Magnetron
filament
heat-up
time is not included.
(about
2
sec.)
?
The water is
stirred,
to
equalize temperature
throughout
the
vessel,
prior
to
measuring
the final
water
temperature.
?
Stirring
devices and
measuring
instruments are
selected
in
order to minimize addition or removal of
heat.
4)
Remove three screws
securing
the PCB
SUB ASM
from the control
panel.
5)
Remove the
digitron
window.
NOTE
:
Remove the leadwire and connector
VERY
CAREFULLY. Be sure to
grasp
the connector
and not the wires.
Measurement of Microwave Power
Output
5-3
Disassembly
and
Adjustment
Water Load
Turn Table
Control
Panel
Spring
PCB
Assembly
Button
Window
Button
Button
Release Lever
4187
(!T)
T

D.
DOOR GROSS ASSEMBLY REMOVAL
1) Open
the door.
2)
Remove the choke cover
cap
very carefully
with
a flat-
blade screwdriver.
CAUTION
:
Be careful not to
damage
door seal
plate
with
the screwdriver.
3)
Lift
up
and
push
the door.
NOTES
1.
After
replacing
the
door,
be sure to check that the
primary
switch,
monitor
switch,
and
secondary
switch
operate
normally.
2.
After
replacing
the
door,
check for microwave
energy
leakage
with
a
survey
meter. Microwave
energy
must be
below the
limit
of
4
mW/cm2.
(with
a 275
ml
water
load)
3. When
mounting
the door
assembly
to the oven
assembly,
be sure to
adjust
the door
assembly
parallel
to
the chassis. Also
adjust
so the door has no
play
between
the inner door surface and oven frame
assembly.
If
the
door
assembly
is not mounted
properly,
microwaves
may
leak from the clearance between the door and the oven.
5-4
Door seal
plate
Remove the choke cover
cap
Remove door

E.
MAGNETRON REMOVAL
1)
Disconnect the leadwire from
high voltage
transformer and
high voltage
capacitor.
2)
Carefully
remove the
mounting
screws
holding
the
magnetron
and the
waveguide.
3)
Remove the
magnetron
assembly
until the tube is
clear from the
waveguide.
NOTES
1.
When
removing
the
magnetron,
make sure its dome
does not
hit
any
adjacent parts,
or
it
may
be
damaged.
2.
When
replacing
the
magnetron,
be sure to install the
magnetron gasket
in
the correct
position
and be sure
that the
gasket
is
in
good
condition.
3. After
replacing
the
magnetron,
check for microwave
energy leakage
with
a
survey
meter around the
magnetron.
Microwave
energy
must be below the
limit
of 5mW/cm2.
(With
a 275
ml.
water
load).
Make sure that
gasket
is
rigidly
attached to the
magnetron.
To
prevent
microwave
leakage, tighten
the
mounting
screws
properly
making
sure there is no
gap
between the
waveguide
and the
magnetron.
5-5
Wave Guide
Magnetron
Noise Filter
Ass'y
Fan Motor
Guide Suction
H.V
Capacitor
H.V.C Bracket
H.V
Diode
C. Protector
Air
Duct
Oven
Lamp

F.
NOISE
FILTER
ASS'Y HIGH VOLTAGE
DIODE,
HIGH VOLTAGE
CAPACITOR,
AND
COOLING
FAN
MOTOR REMOVAL
1
)
Disconnect lead wires from the noise filter
ass'y
and
remove screw
securing
the noise filter earth wire to
the back
plate.
2)
Push two hook of the
guide
suction and
lift
up
the rear
of noise filter
ass'y.
3)
Disconnect lead wires from
H.V.
capacitor
and
remove screw
securing
the
H.V.
diode earth wire to
the back
plate.
4)
Disconnect each lead wires from the AC
relay
and the
fan motor.
5)
Remove two screws
securing
the
guide
suction
ass'y
to the back
plate
and
lift
up
the
guide
suction
ass'y.
6)
Remove one screw from
H.V.
capacitor
bracket.
7)
Pull
H.V.
capacitor
bracket from the
guide
suction.
8)
Remove the fan from the fan motor.
9)
Remove two screws
securing
the fan motor to the
guide
suction and
lift it
up.
G. OVEN
LAMP
REMOVAL
1)
Disconnect the wire leads from oven
lamp.
2)
Remove one screw
securing
the
Air
Duct to the
magnetron.
3)
Push hook to
Right
and Left of
Air
Duct,
with
Drive.
4)
Lift
the oven
Lamp up.
H.
HIGH VOLTAGE TRANSFORMER
REMOVAL
1)
Disconnect the wire leads from the transformer to the
magnetron,
C. Protector
ASS'Y
assembly.
2)
Remove four screws
securing
the
H.V.
transformer to
the base
plate.
3)
Lift
the
H.V.
transformer
up.
I.
C-MOTOR,
THERMISTOR
AND
SHEATH
HEATER
REMOVAL
1)
Remove the two screws
securing
the cover
assembly
to the oven
cavity.
2)
Disconnect the leadwire from the circulation motor
terminal and the sheath heater.
3)
Remove the screws of the
thermistor,
guide
assy-
chamber and
lift
up
the
guide
assy-chamber.
4)
Remove a hex nut
securing
the circulation fan to shaft
of the C-motor.
5)
Remove screws
securing
the motor bracket to the
guide
assy-chamber.
6)
Remove two hex nuts
securing
the C-motor to the
motor bracket.
5-6
H.V.
Transformer

J. TURNTABLE MOTOR REMOVAL
1)
Remove the turntable.
2)
Remove the turntable shaft
VERY
CAREFULLY
with
a slotted screw driver.
3)
Lay
the set down on its back.
4)
Remove the turntable motor cover. The turntable
motor base cover is
easily
removed
by
pinching
the
six
parts
with
a wire
cutting.
5)
Disconnect the lead wires from the turntable motor
terminals.
6)
Remove two screws
securing
the turntable motor to
the oven
cavity assembly.
7)
Lift
the turntable motor and mount turntable motor.
8)
After
repairing
the
motor,
fit
the turntable motor
cover's
projecting
part
to the base
plate's
slit.
K.
INTERLOCK SYSTEM
1)
INTERLOCK MECHANISM
The door lock mechanism is a device which has been
specially
designed
to
completely
eliminate microwave
activity
when the door is
opened
during cooking
and
thus to
prevent
the
danger resulting
from the
microwave
leakage.
2)
MOUNTING OF
THE
PRIMARY,
MONITOR
AND
SECONDARY SWITCH TO
THE
LATCH
BOARD
3)
INSTALLATION
AND
ADJUSTMENT OF
THE
LATCH
BOARD TO
THE
OVEN ASSEMBLY
?
Mount the latch board to the oven
assembly.
?
Adjust
the latch board
in
the arrow direction so the
oven door
will
not have
any play
in
it
when the door is
closed.
?
Tighten
the
mounting
screw.
?
Check for
play
in
the door
by
pushing
the door
release button. Door movement should be less than
0.5mm.
(1/64inch)
Don't
push
the door release button while
making
adjustment.
Make sure that the latch moves
smoothly
after
adjustment
are
completed
and that the screws
are
tight.
Make sure the
primary/monitor/secondary
switch
operate
properly by
following
the
continuity
test
procedure.
5-7
PRIMARY
SWITCH
MONITOR
SWITCH
SECONDARY
SWITCH
ADJUSTMENT
DIRECTION

A. PRIMARY
INTERLOCK SWITCH TEST
When the door button is
slowly
depressed
with
the
door
closed,
an audible "click" should be heard at
the same time or
successively
at intervals. When
the button is
slowly
released,
the latches should
activate the switches
with
an audible "click".
If
the latches do not activate the switches when the
door is
closed,
the switches should be a
adjusted
in
accordance
with
adjustment procedure.
Disconnect
the wire lead from the
primary
switch. Connect the
multimeter leads to the common
(COM)
and
normally
open (NO)
terminal of the switch. The
meter should indicate an
open
circuit
in
the door
open
condition.
When the door is
closed,
the meter should indicate
a closed circuit.
When the
primary
switch
operation
is
abnormal,
make the
necessary
adjustment
or
replace
the
switch
only
with
the same
type
of switch.
B.
SECONDARY INTERLOCK SWITCH TEST
Disconnect the wire lead from the
secondary
switch.
Connect the multimeter leads to the common
(COM)
and
normally
open (NO)
terminals of the switch. The
meter should indicate a
open
condition. When the
door is
closed,
meter should indicate an closed
circuit. When the
secondary
switch
operation
is
abnormal,
make the
necessary
adjustment
or
replace
the switch
only
with
the same
type
of switch.
C. MONITOR SWITCH TEST
Disconnect the wire lead from the monitor switch.
Connect the multimeter leads to the common
(COM)
and
normally
close
(NC)
terminals of the switch. The
meter should indicate closed circuit
in
the door
open
condition. When the door is
closed,
meter should
indicate an closed circuit.When the monitor switch
operation
is
abnormal,
replace
the same
type
of
switch.
Interlock
continuity
Test
5-8
COMPONENTS TEST PROCEDURE RESULTS
SWITCHES Check for
continuity
of the switch
(Wire
leads
removed)
with
a Multi-meter
Primary
Switch
Monitor
Switch
Secondary
Switch
NOTE:
After
checking
for the
continuity
of
switches,
make sure that are
correctly
connected.
Door
open
Door
close
COM
NO
COM
NC
COM
NO
WARNING
:
FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION
EMISSION,REPLACE
ONLY
WITH
IDENTICAL REPLACEMENT RARTS.
TYPE
NO. SZM-V
16-FA-63
OR VP-533A-OF FOR
PRIMARY /
SECONDARY SWITCH
TYPE
NO. SZM-V
16-FA-62
OR VP-532A-OF FOR MONITOR SWITCH

Component
Test Procedure
5-9
CAUTIONS
1.
DISCONNECT
THE
POWER SUPPLY CORD FROM
THE
OUTLET
WHENEVER
REMOVING
THE
OUT
CASE FROM
THE
UNIT.
PROCEED
WITH THE
TEST ONLY
AFTER
DISCHARGING
THE
HIGH
VOLTAGE CAPACITOR
AND
REMOVING
THE WIRE
LEADS FROM
THE PRIMARY
WINDING
OF
THE
HIGH
VOLTAGE TRANSFORMER.
(SEE
PAGE
5)
2. ALL
OPERATIONAL CHECKS
WITH
MICROWAVE
ENERGY
MUST
BE
DONE
WITH A
LOAD
(1
LITER
OF
WATER IN
CONTAINER)
IN THE
OVEN.
COMPONENTS TEST PROCEDURE RESULTS
HIGH
VOLTAGE
TRANSFORMER
(Wire
leads
removed)
1.
Measure the resistance.
(Multi-meter
scale:
R X
1)
?
Primary
winding
Approx:
1.4 !
?
Secondary
winding
Approx:
90
!
?
Filament
winding
Less than: 0.1
!
2.
Measure the resistance.
(Multi-meter
scale:
R X
1000)
?
Primary
winding
to
ground
Normal:
∀.
?
Filament
winding
to
ground
Normal:
∀.
MAGNETRON
1.
Measure the resistance.
(Wire
leads
removed) (Multi-meter
scale:
R X
1)
?
Between filament terminals Normal: Less than
1 !
2.
Measure the resistance.
(Multi-meter
scale:
R X
1000)
?
Filament to chassis. Normal:
∀.
Secondary
Winding
Filament
Winding
Terminal
Filament
Winding
Terminal
Primary
Winding

5-10
COMPONENTS TEST PROCEDURE RESULTS
HIGH
VOLTAGE
CAPACITOR
Antenna
Gasket
Filament
Terminals
Chassis
Normal
:
Momentary
indicates
several
ohms,
and
then
gradually
returns to infinite.
Normal
: ∀.
NOTE
:
When
testing
the
magnetron,
be sure to install the
magnetron gasket
in
the correct
position
and be sure that the
gasket
is
in
good
condition.
Measure the resistance.
(Multi-meter
scale
: R x
1000)
?
Terminal to termonal.
Measure the resistance.
(Multi-meter
scale
: R x
1000)
?
Terminal to case.
Measure the
continuity
(Forward).
(Multi-meter
scale
: R x
10000)
Measure the
continuity
(Reverse).
(Multi-meter
scale
: R x
10000)
Normal
: ∀.
Abnormal
:
Continuity.
Normal
:
Continuity.
Abnormal
: ∀.
HIGH
VOLTAGE
DIODE
NOTE
:
Some
inexpensive
meter
may
indicate
infinite resistance
in
both direction.