Daewoo KOC-9N4T7S, Service Manual

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21
8. TROUBLE SHOOTING GUIDE
Following the procedure below to check if the oven is defective or not.
1) Check grounding before trouble checking.
2) Be careful of the high voltage circuit.
3) Discharge the high voltage capacitor.
4) When checking the continuity of the switches, fuse or high voltage tranformer, disconnect one load wire from these
parts and check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to
your meter.
(TROUBLE 1) Oven does not operate at all : any inputs can not be accepted.
NOTE : When electric parts are checked, be sure the power cord is not inserted the wall outlet.
Check wire harness, wiring and connection of the terminals and power cord before check the parts listed below.
CONDITION CHECK
Check continuity of
interlock monitor switch with
door closed
( COM
NC )
Check continuity of
both primary and secondary
interlock switch with door closed
Malfunction of
Interlock
monitor switch
Malfunction of
interlock switch
RESULT
Continuity
No continuity
CAUSE REMEDY
Replace
(COM NC)
Fuse blows.
Replace
Shorted contacts
of primary
interlock Switch
Continuity Replace
Check continuity of
primary interlock switch contact
with door partially open until
interlock monitor switch contact
close
( COM
NC close )
Defective low
voltage
transformer
Defective
high voltage
transformer
or infinite Replace
Replace
Check continuity of
primary winding of low voltage
transformer
Disconnect high voltage
fuse and operate the unit
No
Continuity
Continuity
Approx.
480 ~620
( normal )
Fuse again
blows