Component Test Procedure - LG MS-194A Service Manual

COMPONENT TEST PROCEDURE

CAUTIONS
1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE
OUTER 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 2-1)
2. ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD (1 LITER
OF WATER IN CONTAINER) IN THE OVEN.
COMPONENTS
HIGH VOLTAGE
TRANSFORMER
(Wire leads removed)
MAGNETRON
(Wire leads removed)
TEST PROCEDURE
FILAMENT
WINDING
TERMINAL
PRIMARY
TERMINAL
1. Measure the resistance.
(Ohm-meter scale: Rx1)
• Primary winding
• Secondary winding
• Filament winding
2. Measure the resistance.
(Ohm-meter scale: Rx1000)
• Primary winding to ground
• Filament winding to ground
1. Measure the resistance.
(Ohm-meter scale: Rx1)
• Between Filament terminal
2. Measure the resistance.
(Ohm-meter scale: Rx1000)
• Filament to chassis
5-8
SECONDARY
TERMINAL
Approx.: 2.5 Ω
Approx.: 110 Ω
Less than: 0.4 Ω
Normal: ∞
Normal: ∞
Normal: Less than 1 Ω
Normal: ∞
RESULTS