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and should

repair any unit found to have excessive emission levels
at no cost to the owner and should ascertain the cause
of the excessive leakage. The service personnel
should instruct the owner not to use the unit until the
oven has been brought into compliance.

• The service personnel should check all surface and

vent openings for microwave leakage.

• Check for microwave leakage after every servicing.

The power density of the microwave radiation leakage
emitted by the microwave oven should not exceed 
4 mW/cm

2

. Always start measuring of an unknown field

to assure safety for operating personnel from radiation
leakage.

5-1

Tools normally used for TV servicing are sufficient.
Standard tools are listed below.

• Diagonal pliers
• Long nose pliers
• Phillips screwdriver
• Flat blade screwdriver
• Wrench (size 5mm)
• Nutdriver (size 5mm)
• Adjustable wrench
• Soldering iron
• Solder
• Vinyl insulation tape
• Polishing cloth

• TESTER(VOLTS-DC, AC., Ohmmeter)
• Microwave survey meter

- Holaday HI-1500

HI-1501

- Narda     8100

8200

• Inch scale
• 600 cc non conductive material beaker (glass or plastic),

inside diameter: approx. 8.5 cm(3

1

/2

in.)

• Cylindrical and made of borosilicate glass vessel.

max. thickness: 3 mm
outside diameter: approx. 190mm
height: approx. 90mm

• Glass thermometer: 100°C or 212°F (1 deg scale)

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