LG MC-805AR Service Manual ▷ View online
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.
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.
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.
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.
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
SECONDARY
SWITCH
ADJUSTMENT
DIRECTION
MONITOR
SWITCH
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.
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.
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.
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
Switch
Monitor
Switch
Switch
Secondary
Switch
Switch
NOTE: After checking for the continuity of switches, make sure that are
correctly connected.
Door
open
open
Door
close
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
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)
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)
TRANSFORMER
(Wire leads removed)
1. Measure the resistance.
(Multi-meter scale: R X 1)
• Primary winding
• Primary winding
Approx: 1.4
Ω
• Secondary winding
Approx: 90
Ω
• Filament winding
Less than: 0.1
Ω
2. Measure the resistance.
(Multi-meter scale: R X 1000)
• Primary winding to ground
• 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
• Between filament terminals
Normal: Less than 1
Ω
2. Measure the resistance.
(Multi-meter scale: R X 1000)
• Filament to chassis.
• Filament to chassis.
Normal:
∞
.
Secondary
Winding
Filament
Winding
Terminal
Filament
Winding
Terminal
Primary
Winding
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)
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)
TRANSFORMER
(Wire leads removed)
1. Measure the resistance.
(Multi-meter scale: R X 1)
• Primary winding
• Primary winding
Approx: 1.4
Ω
• Secondary winding
Approx: 90
Ω
• Filament winding
Less than: 0.1
Ω
2. Measure the resistance.
(Multi-meter scale: R X 1000)
• Primary winding to ground
• 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
• Between filament terminals
Normal: Less than 1
Ω
2. Measure the resistance.
(Multi-meter scale: R X 1000)
• Filament to chassis.
• Filament to chassis.
Normal:
∞
.
Secondary
Winding
Filament
Winding
Terminal
Filament
Winding
Terminal
Primary
Winding