Samsung Electronics
7-5
Troubleshooting
7-4 Electrical Malfunction
SYMPTOM
CAUSE
CORRECTIONS
Oven is dead.
1. Open or loose lead wire harness
Check fan motor when thermal cutout is defective.
Fuse is OK.
2. Open thermal cutout (Magnetron)
No display and no operation at all.
3. Open low voltage transformer
Check Ass'y PCB when LVT is defective.
4. Defective Ass'y PCB
No display and no operation at all.
1. Shorted lead wire harness
Check adjustment of primary, interlock monitor,
Fuse is blown.
2. Defective primary latch switch (NOTE 1)
secondary switch.
3. Defective monitor switch (NOTE1)
4. Shorted HVCapacitor
5. Shorted HVTransformer (NOTE2)
NOTE 1: All of these switches must be replaced at the same time.
(refer to adjustment instructions)
Check continuity of power relay contacts and if it has continuity, replace power
relay also.
NOTE 2: When HVTransformer is replaced, check diode and magnetron also.
Oven does not accept
1. Key input is not in-Sequence
Refer to operation procedure.
key input (Program)
2. Open or loose connection of
sub-PCB to main PCB.
3. Squeeted buttons
4. Defective Ass'y PCB
Replace PCB main.
1. Off-alignment of latch switches
Adjust door and latch switches.
2. Open or loose connection of high voltage
circuit especially magnetron filament
circuit
NOTE: Large contact resistance will bring
lower magnetron filament voltage and
Timer starts countdown but no
cause magnetron to lower output and/or
microwave oscillation.
intermittent oscillation.
(No heat while oven lamp and
3. Defective high voltage components
Check high voltage component according to
fan motor turn on.)
H.V.Transformer
component test procedure and replace if it is
H.V.Capacitor
defective.
H.V.Diode
Magnetron
4. Open or loose wiring of power relay
5. Defective primary latch switch
6. Defective power relay or Ass'y PCB
Replace PCB main.