LG MB-392A Service Information page 13

(TROUBLE 1) Oven lamp does not turn on when the timer knob is pushed with door closed.
CONDITION
1. Fuse blows.
This fuse is a special type of fuse which is kept as spare part by the importer.
NOTE : All these switches must be replaced at the same time.
(TROUBLE 2) Oven does not start even though the timer is set.
CONDITION
1. Oven does not
operate.
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
Check the
continuity of the
primary switch
with door
closed.
Check the
continuity of the
secondary
switch with
secondary
switch pushed.
RESULT
Continuity.
No continuity.
Continuity.
No continuity.
Normal.
Fuse blows again
RESULT
No continuity.
No continuity.
5-13
CAUSE
Malfunction of the
monitor switch.
Shorted contact at
the primary switch.
Defective high
voltage capacitor.
Defective high volt-
age transformer.
CAUSE
Malfunction of the
primary switch.
Malfunction of the
secondary switch.
REMEDY
Replace fuse,
primary, monitor
and secondary
switches.
Replace fuse,
primary, monitor
and secondary
switches.
Replace high
voltage capacitor.
Replace high volt-
age transformer.
REMEDY
Adjust or replace.
Adjust or replace.