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5-10

FUSE

HEATER ELEMENT
(Wire leads removed.)

MAGNETRON
THERMOSTAT

Check for continuity of the fuse with an
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.

NOTE: Make sure heater is fully cooled when tested.

Measure the resistance.
(Multi-meter scale: Rx1)

Normal:
*Grill heater

Approx. 42 ohm
(at 20 ~ 30

o

C)

*Convection heater

Approx. 40 ohm
(at 20 ~ 30

o

C)

Normal: more than 0.5 Mohm

Normal               Abnormal

Measure the resistance with 500V-100M ohm
insulation resistance meter.

0°C~Approx.90°C   Approx.90°C

0°C~Approx.145°C Approx.145°C

5-11

Disconnect the 8 pin
connector from P.C.B.
(Refer to schemetic diagram)

RELAY 2, RELAY 3
OF P.C.B.
(Wire leads removed.)
Note: Relay
Relay 1:  Fan motor

Turntable motor
Oven lamp

Relay 2: Microwave
Relay 3: Grill

FAN MOTOR
(Wire leads removed)

TURNTABLE
MOTOR
(Wire leads removed)

Check for P.C.B. connector.

Measure the resistance.
(Ohm-meter scale: R x 1)

Measure the resistance.
(Ohm-meter scale: R x 1000)

Normal: Approx. 200 ~400 ohm

Abnormal: Infinite or several 

ohm.

Normal: Approx. 10~20 kohm
Abnormal: Infinite or several 

ohm.

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

CONNECTOR, NOT THE WIRES.

A

B

Cooking Start             OFF

1

3

5

Relay 2

Relay 1

Relay 3

Cooking Start             OFF

A    Approx. 30 ~ 50 ohm 

B    Approx. 300 ~ 500 ohm

CIRCULATION MOTOR
(Wire leads removed)

NOTE:
*(     ) = WIRE COLOR

RELAY 4, 6 OF P.C.B
(Disconnect the 9 pin 
connector from P.C.B)
See Schematic Dagram on
page 4-3)

RELAY 2, 3, 5 OF P.C.B
(Wire leads removed.)
RY2 : Microwave
RY3 : Grill
RY5 : Convection

Normal : COM-230V : Approx. 150 

Ω

Abnormal : Infinite or several ohm.

NOTE : A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS

SERVICED FOR ANY REASON.
MAKE SURE THE WIRE LEADS ARE CORRECT POSITION.
WHEN REMOVING THE WIRE LEAD FROM THE PARTS, BE SURE TO GRASP THE
CONNECTOR, NOT THE WIRES.

5-12

Cooking Start

OFF

Cooking Start

OFF

COM
(YL)

230V(BL)

CN2

1

3

5

7

9

Relay 4

Relay 6

Relay 2 Relay 3 Relay 5

5-13

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.

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

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.

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.

Microwave oven 

does not work.

Inserting many plug into one
plug outlet and using 
them at the same time 
(causes overloading).

Microwave oven plug is not
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.

Sparks occurring.

Inconsistent intensity of
microwave by their
characteristics.

1. Wrap the thinner part with

aluminum foil.

2. Use plastic wrap or lid.
3. Stir once or twice while

cooking soup, cocoa or
milk, etc.

Uneven cooking.

Ceramic ware trimmed in
gold or silver powder is used.

Avoid using other electrical
appliances when you use the
microwave oven.

Insert microwave oven plug
securely.

Use the microwave oven at
adequate line voltage.

This may not be a defect.
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.

Do not use any type of
cookware with metallic
trimming.