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3828W5S1278(S/M) 1p~19p  99.9.18 8:34 AM  ˘

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This device is to be serviced only by properly qualified service personnel.
Consult the service manual for proper service procedures to assure continued safety operation and for precautions to be
taken to avoid possible exposure to excessive microwave energy.

A) Do not operate or allow the oven to be operated with the door open.

B) Make the following safety checks on all ovens to be serviced before activating the magnetron or other

microwave source, and make repairs as necessary; (1) interlock operation, (2) proper door closing,  (3)

seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and

latches, (5) evidence of dropping or abuse.

C) Before turning on microwave power for any service test or inspection within the microwave generating

compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment,

integrity, and connections.

D) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave generation

and transmission systems shall be repaired, replaced, or adjusted by procedures described in this manual

before the oven is released to the owner.

E) A microwave leakage check should be performed on each oven prior to release to the owner.

DO NOT BECOME EXPOSED TO RADIATION FROM THE MICROWAVE GENERATOR
OR OTHER PARTS CONDUCTING MICROWAVE ENERGY.

MICROWAVE/GRILL OVEN

BEFORE SERVICING THE UNIT, READ THE
SAFETY PRECAUTIONS IN THIS  MANUAL.

5-9

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)

2. ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD (1 LITER OF

WATER IN CONTAINER) IN THE OVEN.

HIGH VOLTAGE
TRANSFORMER
(Wire leads removed)

1. Measure the resistance.

(Multi-meter scale: R x 1 and R x 100)
• Primary winding 

Approx: 0.3 ~ 0.6 

Ω

• Secondary winding 

Approx: 70 ~ 100 

Ω

• Filament winding 

Less than: 1 

Ω

2. Measure the resistance.

(Multi-meter scale: R x 1000)
• Primary winding to ground 

Normal: 

infinite

• Filament winding to ground 

Normal: 

infinite

MAGNETRON 

1. Measure the resistance.

(Wire leads removed)

(Multi-meter scale: R x 1)
• Between filament terminals

Normal: Less than 1 

Ω

2. Measure the resistance.

(Multi-meter scale: R x1000)
• Filament to chassis.

Normal: 

infinite

PRIMARY  
TERMINAL

FILAMENT 
WINDING

SECONDARY  

WIRE