LG MH-6322W Service Manual ▷ View online
5-10
COMPONENTS
TEST PROCEDURE
RESULTS
FUSE
HEATER ELEMENT
(Wire leads removed.)
(Wire leads removed.)
GRILL THERMOSTAT
OVEN THERMOSTAT
MAGNETRON
THERMOSTAT
MAGNETRON
THERMOSTAT
Check for continuity of the fuse with an
multi-meter.
multi-meter.
NOTE: If the fuse is blown, check the primary, the secondary, and the monitor
switches, H.V.D. and H.V.C. before replacing the fuse.
If the fuse is blown by improper switch operation replace the defective switch
and the fuse at the same time. Replace just the fuse if the switches operate
normally.
switches, H.V.D. and H.V.C. before replacing the fuse.
If the fuse is blown by improper switch operation replace the defective switch
and the fuse at the same time. Replace just the fuse if the switches operate
normally.
NOTE: Make sure heater is fully cooled when tested.
Measure the resistance.
(Multi-meter scale: Rx1)
(Multi-meter scale: Rx1)
Normal:
*Grill heater
*Grill heater
Approx. 50
Ω
(at 20 ~ 30°C)
Normal: more than 200 M
Ω
Normal Abnormal
Measure the resistance with 500V-100M ohm
insulation resistance meter.
insulation resistance meter.
0°C~Approx.90°C Approx.90°C
0°C~Approx.145°C Approx.145°C
5-11
COMPONENTS
TEST PROCEDURE
RESULTS
TIMER MOTOR
(Wire leads removed)
FAN MOTOR
(Wire leads removed)
(Wire leads removed)
TURNTABLE
MOTOR
(Wire leads removed)
MOTOR
(Wire leads removed)
Check for continuity of timer motor with an
ohm-meter.
(Remove wire leads from timer motor)
ohm-meter.
(Remove wire leads from timer motor)
Measure the resistance.
(Ohm-meter scale: R x 1)
(Ohm-meter scale: R x 1)
Measure the resistance.
(Ohm-meter scale: R x 1000)
(Ohm-meter scale: R x 1000)
Normal:
Abnormal:
∞
or several
Ω
Normal: Approx. 100~200
Ω
Abnormal:
∞
or several
Ω
NOTE : • A MICROWAVE LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS
SERVICED FOR ANY REASON.
• MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION.
• WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE
• WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE
CONNECTOR, NOT THE WIRES.
A
B
C
Turn On Turn Off
A
B
Grill Switch
Microwave Switch
Approx. 22 K
Ω
Note : A is timer ON, OFF
switch.
B is power supply
terminal of the timer
motor.
B is power supply
terminal of the timer
motor.
A ~ B A ~ C
30 ~ 50
Ω
300~500
Ω
A
B
5-12
TROUBLE SHOOTING
WHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER, EVALUATE THE COMPLAINT CAREFULLY. IF
THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE
MICROWAVE OVEN. THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL.
THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE
MICROWAVE OVEN. THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL.
CAUTIONS
1. Check grounding before checking for trouble.
2. Be careful of the high voltage circuit.
3. Discharge the high voltage capacitor. (See page 2-1)
4. When checking the continuity of the switches or of the high voltage transformer, disconnect one lead wire
2. Be careful of the high voltage circuit.
3. Discharge the high voltage capacitor. (See page 2-1)
4. When checking the continuity of the switches or of the high voltage transformer, disconnect one lead wire
from these parts and then check continuity with the AC plug removed. To do otherwise may result in a
false reading or damage to your meter.
false reading or damage to your meter.
5. Do not touch any part of the circuitry on the digital programmer circuit since static electric discharge may
damage this control panel.
Always touch yourself ground while working on this panel to discharge any static charge built up in your
body.
CONDITION
Microwave oven
does not work.
Inserting many plug into one
plug outlet and using
them at the same time
(causes overloading).
plug outlet and using
them at the same time
(causes overloading).
Microwave oven plug is not
inserted tightly.
inserted tightly.
Output power is too low.
Low AC input voltage.
Food temperature is too low.
Using metallic ware and
allowing it to touch the oven
wall.
allowing it to touch the oven
wall.
Sparks occurring.
Inconsistent intensity of
microwave by their
characteristics.
microwave by their
characteristics.
1. Wrap the thinner part with
aluminum foil.
2. Use plastic wrap or lid.
3. Stir once or twice while
3. Stir once or twice while
cooking soup, cocoa or
milk, etc.
milk, etc.
Uneven cooking.
Ceramic ware trimmed in
gold or silver powder is used.
gold or silver powder is used.
Avoid using other electrical
appliances when you use the
microwave oven.
appliances when you use the
microwave oven.
Insert microwave oven plug
securely.
securely.
Use the microwave oven at
adequate line voltage.
adequate line voltage.
This may not be a defect.
It is possible that the food
should be cooked for a
longer time period.
It is possible that the food
should be cooked for a
longer time period.
Do not use metallic ware for
cooking except where noted
in the cooking guide.
cooking except where noted
in the cooking guide.
Do not use any type of
cookware with metallic
trimming.
cookware with metallic
trimming.
CAUSE
REMEDY
5-13
CONDITION
CHECK
RESULT
CAUSE
REMEDY
1. Fuse blows.
Continuity.
No continuity.
Continuity.
Shorted contact at
the primary switch.
the primary switch.
Replace fuse,
primary, monitor
and secondary
switches.
primary, monitor
and secondary
switches.
No continuity.
Normal.
Defective high
voltage capacitor.
voltage capacitor.
Replace high
voltage capacitor.
voltage capacitor.
Fuse blows again
Defective high volt-
age transformer.
age transformer.
Replace high volt-
age transformer.
age transformer.
Malfunction of the
monitor switch.
monitor switch.
Replace fuse,
primary, monitor
and secondary
switches.
primary, monitor
and secondary
switches.
Check continuity
of monitor
switch (with
door closed).
of monitor
switch (with
door closed).
Check continuity
of primary
switch (with
door opened).
of primary
switch (with
door opened).
Disconnect one
side of the wire
lead connected
from transformer
to the high
voltage
capacitor and
operate the unit.
side of the wire
lead connected
from transformer
to the high
voltage
capacitor and
operate the unit.
Replace fuse
1. Oven does not
operate.
No continuity.
No continuity.
Adjust or replace.
Malfunction of the
primary switch.
primary switch.
Malfunction of the
secondary switch.
secondary switch.
Adjust or replace.
Check the
continuity of the
primary switch
with door
closed.
continuity of the
primary switch
with door
closed.
Check the
continuity of the
secondary
switch with
secondary
switch pushed.
continuity of the
secondary
switch with
secondary
switch pushed.
(TROUBLE 1) Oven lamp does not turn on when the timer knob is pushed with door closed.
(TROUBLE 2) Oven does not start even though the timer is set.
NOTE : All these switches must be replaced at the same time.
This fuse is a special type of fuse which is kept as spare part by the importer.
CONDITION
CHECK
RESULT
CAUSE
REMEDY
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