LG Electronics MV1825SW Test and Checkout PROCEDURES, and Trouble Shooting, Test Procedures

TEST AND CHECKOUT PROCEDURES, AND TROUBLE SHOOTING

- CAUTIONS -

-DISCONNECT THE POWER SUPPLY CORD FROM THE WALL OUTLET WHENEVER REMOVINGING THE CABINET FROM THE UNIT. PROCEED WITH THE TESTS ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER. (SEE FIGURE 24)

-ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD (1 LITER OF WATER IN CONTAINER) IN THE OVEN.

A. TEST PROCEDURES

Secondary

Winding

Filament

Winding

Primary

Winding

Figure 24

COMPONENTS		TEST PROCEDURES	RESULTS
	1)	Measure the resistance: Across the
		filament terminals of the magnetron	Normal reading:
		with an ohm-meter on Rx1 scale.	Less than 1 ohm.
	2)	Measure the resistance: Between	Normal reading:
MAGNETRON		each filament terminal of the	Infinite ohms.
(Wire leads are		magnetron and the chassis ground
removed)		with an ohm-mater on high test scale.	NOTE: Replace the magnetron, if the
			magnetron checks and all of the
			high voltage component tests are
			good, but the unit still does not heat
			a load.
	1)	Measure the resistance:
		With an ohm-meter on Rx1 scale.	Normal readings:
HIGH-VOLTAGE		a. Primary winding;	Approx. 0.2 to 0.5 ohm.
TRANSFORMER		b. Filament winding;	Less than 0.1 ohm.
(Wire leads are		c. Secondary winding;	Approx. 50 to 120 ohms.
removed)
	2)	Measure the resistance:
		With an ohm-meter on highest scale.	Normal readings:
		a. Primary winding to ground;	Infinite ohms.
		b. Filament winding to ground;	Infinite ohms.

NOTE: A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON.

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