Troubleshooting Guide - Daewoo KOC-1M0K9S Service Manual

8. TROUBLESHOOTING 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.
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.
(TROUBLE 1) Oven does not operate at all : any inputs can not be accepted.
CONDITION
Fuse blows.
Check continuity of
interlock monitor switch with
door closed
( COM NC )
Check continuity of
both primary and secondary
interlock switch with door closed
Check continuity of
primary interlock switch contact with
door partially open until interlock
monitor switch contact close
( COM NC close )
Check continuity of
primary winding of low voltage
transformer
Disconnect high voltage
fuse and operate the unit
CHECK
18
RESULT
Continuity
Malfunction of
Interlock
(COM NC)
monitor switch
No continuity
No
Malfunction of
Continuity
interlock switch
Continuity
Continuity
Shorted contacts
of primary
interlock Switch
0 Ω or infinite
Defective low
voltage
transformer
Approx.
530Ω
( normal )
Fuse again
Defective
blows
high voltage
transformer
CAUSE REMEDY
Replace
Replace
Replace
Replace
Replace