LG Electronics MS3447GRS service manual Result, 5-13, Condition, Check, Cause, Remedy

(TROUBLE 2) Oven does not operate at all, Display window does not display any figures, and no input is accepted.

CONDITION

1. Fuse blows.

CHECK	RESULT
Check continuity	Continuity.
of monitor
switch (with
door closed).	No continuity.
Replace fuse

CAUSE

Malfunction of the monitor switch.

REMEDY

Replace fuse, primary, monitor, secondary switches, and RELAY(RY2) of P.C.B Assembly.

Check continuity	Continuity.
of primary
switch (with
door opened).	No continuity.

Check continuity	Continuity.
of secondary
switch (with
door opened).	No continuity.

Shorted contact at the primary switch.

Malfunction of secondary switch.

Replace fuse, primary, monitor, secondary switches, and RELAY(RY2) of P.C.B Assembly.

Replace fuse, primary, monitor, secondary switches, and RELAY(RY2) of P.C.B Assembly.

Disconnect one	Normal.
side of the wire
lead connected
from transformer	Fuse blows again
to the high
voltage
capacitor and
operate the unit.

Defective high	Replace high
voltage capacitor.	voltage capacitor.
Defective high volt-	Replace high volt-
age transformer.	age transformer.

NOTE : All these switches must be replaced at the same time. Refer to page 5-7, 5-8

2.Fuse does not blow.

Check continuity	No continuity.	Defective
		thermostat.
of thermostat.

	Continuity.
Check continuity	No continuity.	Defective power
of power supply
		supply cord.
cord.

Replace thermostat.

Replace power supply cord.

LGE Internal Use Only	5-13	Copyright © 2007 LG Electronics. Inc. All right reserved.
		Only for training and service purposes