LG MH-657PL, Service Manual

Page: 21 / 42

5-11
COMPONENTS TEST PROCEDURE RESULTS
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