LG MC-8082WRS Service Manual ▷ View online
5-5
H. FAN MOTOR ASSEMBLY REMOVAL
1) Discharge the high voltage capacitor.
2) Disconnect the leadwire from fan motor, noise filter
2) Disconnect the leadwire from fan motor, noise filter
and high voltage capacitor.
3) Remove the two screws holding the the suction guide
ASS’Y to the oven cavity and remove the high voltage
diode earth screw.
diode earth screw.
4) Remove the screw of the capacitor bracket.
5) Remove the two screws holding the fan motor ASS’Y
5) Remove the two screws holding the fan motor ASS’Y
to the suction guide ASS’Y.
I. HIGH VOLTAGE CAPACITOR AND
DIODE REMOVAL
1) Discharge the high voltage capacitor.
2) Disconnect the leadwire from fan motor, noise filter
2) Disconnect the leadwire from fan motor, noise filter
and high voltage capacitor.
3) Remove the screw holding the suction guide ASS’Y to
the oven cavity and remove the high voltage diode
earth screw.
earth screw.
4) Remove the screw holding the high voltage capacitor
bracket.
J. THE TURNTABLE MOTOR REMOVAL
1) Remove the turntable.
2) Remove the turntable shaft VERY CAREFULLY
2) Remove the turntable shaft VERY CAREFULLY
with a slotted screwdriver.
3) Lay the unit down on its back.
4) Remove the turntable motor cover.
4) Remove the turntable motor cover.
The turntable base cover is easily removed by
pinching the six parts with a wire cutting.
5) Disconnect the leadwire from the turntable motor
terminals.
6) Remove the screw securing the turntable motor to
the oven cavity ASS’Y
7) After repairing the motor, rotate the removed
turntable motor cover.
8) Fit the turntable motor cover’s projecting part to the
base plate slit.
NOTE:
1. Remove the wire lead from the turntable motor
1. Remove the wire lead from the turntable motor
VERY CAREFULLY.
2. Be sure to grasp the connector, not the wires, when
removing.
Wire Leads
Turntable Motor
H.V.
Capacitor
Capacitor
H.V.
Transformer
Transformer
Suction
Guide
Guide
Fan Motor ASS’Y
K. 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.
L. PCB ASSEMBLY REMOVAL
1) Remove the control panel assembly from the
cavity. (Refer to control panel assembly removal
on previous page.)
on previous page.)
2) Remove screws which hold the PCB SUB ASS’Y to
the control panel.
3) Take off the PCB SUB ASS’Y from the control
panel.
M. INTERLOCK SYSTEM
1) INTERLOCK MECHANISM
The door lock mechanism is a device which has
been specially designed to eliminate completely
microwave activity when the door is opened during
cooking and thus to prevent the danger resulting
from the microwave leakage.
been specially designed to eliminate completely
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/
SECONDARY SWITCHES 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 that
• Adjust the latch board in the arrow direction so that
oven door will not have any play in it when the door
is closed.
is closed.
• Tighten the mounting screw.
5-6
Latch Board
Secondary Interlock Switch
Interlock Monitor Switch
Primary Interlock Switch
A. PRIMARY INTERLOCK SWITCH TEST
When the door release button is depressed slowly
with the door closed, an audible click should be
heard at the same time or successively at
intervals. When the button is released slowly, 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 the adjustment
procedure. Disconnect the wire lead from the
primary switch. Connect the ohmmeter 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.
with the door closed, an audible click should be
heard at the same time or successively at
intervals. When the button is released slowly, 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 the adjustment
procedure. Disconnect the wire lead from the
primary switch. Connect the ohmmeter 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 ohmmeter leads to the common
(COM) and normally open (NO) terminals of the
switch. The meter should indicate a open circuit in
the door 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.
switch.
Connect the ohmmeter leads to the common
(COM) and normally open (NO) terminals of the
switch. The meter should indicate a open circuit in
the door 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 ohmmeter leads to the common
(COM) and normally closed (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 open circuit. When the
monitor switch operation is abnormal, replace with
the same type of switch.
NOTE: After repairing the door or the interlock
system, it is necessary to do this continuity
test before operating the oven.
Connect the ohmmeter leads to the common
(COM) and normally closed (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 open circuit. When the
monitor switch operation is abnormal, replace with
the same type of switch.
NOTE: After repairing the door or the interlock
system, it is necessary to do this continuity
test before operating the oven.
5-7
WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION
EMISSION, REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS.
TYPE NO. SZM-V 16-FA-63 OR VP-533A-OF FOR PRIMARY SWITCH
TYPE NO. SZM-V 16-FA-61 OR VP-531A-OF FOR MONITOR SWITCH
TYPE NO. SZM-V 16-FA-63 OR VP-533A-OF FOR SECONDARY SWITCH
TYPE NO. SZM-V 16-FA-61 OR VP-531A-OF FOR MONITOR SWITCH
TYPE NO. SZM-V 16-FA-63 OR VP-533A-OF FOR SECONDARY SWITCH
INTERLOCK CONTINUITY TEST
COMPONENTS
TEST PROCEDURE
RESULTS
SWITCHES
Check for continuity of the switch
(Wire leads removed)
with a Multi-meter
Primary
Switch
Switch
Monitor
Switch
Switch
Secondary
Switch
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
5-8
CAUTIONS
1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE
OUTER 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 2-1)
VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE
HIGH VOLTAGE TRANSFORMER. (SEE PAGE 2-1)
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)
TRANSFORMER
(Wire leads removed)
MAGNETRON
(Wire leads removed)
(Wire leads removed)
1. Measure the resistance.
(Ohm-meter scale: Rx1 and Rx100)
• Primary winding
• Secondary winding
• Filament winding
• Primary winding
• Secondary winding
• Filament winding
2. Measure the resistance.
(Ohm-meter scale: Rx1000)
• Primary winding to ground
• Filament winding to ground
• Primary winding to ground
• Filament winding to ground
1. Measure the resistance.
(Ohm-meter scale: Rx1)
• Filament terminal
• Filament terminal
2. Measure the resistance.
(Ohm-meter scale: Rx1000)
• Filament to chassis
• Filament to chassis
Approx.: 1.9 ohm
Approx.: 90 ohm
Less than: 1 ohm
Approx.: 90 ohm
Less than: 1 ohm
Normal: Infinite
Normal: Infinite
Normal: Infinite
Normal: Less than 1 ohm
Normal: Infinite
FILAMENT
WINDING
TERMINAL
WINDING
TERMINAL
PRIMARY
TERMINAL
TERMINAL
SECONDARY
TERMINAL
TERMINAL
COMPONENT TEST PROCEDURE
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