Component Test Procedure - LG MH-794GS Service Manual

Component Test Procedure

CAUTIONS
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.
COMPONENTS
HIGH VOLTAGE
TRANSFORMER
(Wire leads removed)
MAGNETRON
(Wire leads removed)
TEST PROCEDURE
Filament
Winding
Terminal
Primary
Winding
1. Measure the resistance.
(Multi-meter scale: R x 1 and R x 100)
Primary winding
Secondary winding
Filament winding
2. Measure the resistance.
(Multi-meter scale: R x 1000)
Primary winding to ground
Filament winding to ground
1. Measure the resistance.
(Multi-meter scale: R x 1)
Between filament terminals
2. Measure the resistance.
(Multi-meter scale: R x 1000)
Filament to chassis.
21
Filament
Winding
Terminal
Secondary
Winding
Approx: 2 Ω
Approx: 90 Ω
Less than: 1 Ω
Normal: ∞.
Normal: ∞.
Normal: Less than 1 Ω
Normal: ∞.
RESULTS