DAEWOO ELECTRONICS KOC-995T0S, Service Manual

Page: 22 / 52

21
TROUBLE SHOOTING GUIDE
Following the procedures below to check if the oven is defective or not.
1. Check grounding before checking trouble.
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 transformer, disconnect one lead wire from these parts
and then 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.
When electric parts are checked, be sure the power cord is not inserted into the wall outlet.
Check wire harness, wiring, and connected of the terminals and power cord before check parts listed below.
NOTE
CONDITION
CHECK RESULT CAUSE REMEDY
Fuse blows.
Continuity
(COM NC)
¡ê
(COM NC)
¡ ê
No Continuity
No
Continuity
Continuity
Continuity
0 infinite
Ω
or
Approx.
150~210
(normal)
Fuse again
blows
Replace
NOTE 1
Replace
NOTE 1
Replace
NOTE 1
Replace
Replace
Check continuity of
interlock monitor switch
with door closed
(COM NC)
¡ ê
Check continuity of both
primary and secondary
interlock switch with
door closed
Check continuity of
primary winding of low
voltage transformer
Disconnect high voltage
fuse and operate the unit
Check continuity of
primary interlock switch
contact with door
partially open until
interlock monitor switch
contact close
(COM NC close)
¡ê
Malfunction
of interlock
monitor
switch
Malfunction
of interlock
switch
Shorted
contacts of
primary
interlock
switch
Defective low
voltage
transformer
Defective
high voltage
transformer