LG MB-3949G Service Manual page 23

(TROUBLE 1) Oven lamp does not turn on when the timer knob is turned with door closed.
CONDITION
1. Fuse blows.
NOTE : All these switches must be replaced at the same time. Refer to page 5-6, 5-7
2. Fuse does not
blow.
LGE Internal Use Only
CHECK
Check continuity
of monitor
switch (with
door closed).
Replace fuse
Check continuity
of primary
switch (with
door opened).
Disconnect one
side of the wire
lead connected
from transformer
to the high
voltage
capacitor and
operate the unit.
Check continuity
of oven
thermostat.
Check continuity
of power supply
cord.
RESULT
Malfunction of the
Continuity.
monitor switch.
No continuity.
Continuity.
Shorted contact at
the primary switch.
No continuity.
Defective high
Normal.
voltage capacitor.
Defective high volt-
Fuse blows again
age transformer.
No continuity.
Continuity.
No continuity.
5-13
CAUSE
Replace primary
and monitor
switches.
Replace primary
and monitor
switches.
Replace high
voltage capacitor.
Replace high volt-
age transformer.
Defective oven Replace oven
thermostat. thermostat.
Defective power Replace power
supply cord. supply cord.
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Only for training and service purposes
REMEDY