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Samsung Electronics
6. Troubleshooting
PRECAUTION
1. CHECK GROUNDING BEFORE CHECKING FOR TROUBLE.
2. BE CAREFUL OF THE HIGH VOLTAGE CIRCUIT.
3. DISCHARGE THE HIGH VOLTAGE CAPACITOR.
4. WHEN CHECKING THE CONTINUITY OF THE SWITCHES OR TRANSFORMER, DISCONNECT
LEAD WIRES FROM THESE PARTS AND THEN CHECK CONTINUITY WITHOUT THE POWER
SOURCE ON. TO DO OTHERWISE MAY RESULT IN A FALSE READING OR DAMAGE TO YOUR
METER.
5. DO NOT TOUCH ANY PART OF THE CIRCUIT OR THE CONTROL CIRCUIT BOARD, SINCE STATIC
DISCHARGE MAY DAMAGE IT. ALWAYS TOUCH GROUND WHILE WORKING ON IT TO
DISCHARGE ANY STATIC CHARGE BUILT UP.
6-1 Electrical Malfunction
SYMPTOM
CAUSE
CORRECTIONS
Oven is dead.
1. Open or loose lead wire harness
Check magnetron or cavity thermal cutout
Fuse is OK.
2. Open thermal cutout (magnetron, cavity)
switch is defective.
No display and no
3. Open low voltage transformer
Check Ass'y PCB when LVT is defective.
operation.
4. Defective Ass'y PCB
No display and no
1. Shorted lead wire
Check adjustment of primary, interlock
operation
2. Defective primary latch switch (NOTE1)
monitor, door sensing switch.
Fuse blown out.
3. Defective monitor switch (NOTE1)
(10A, 1.6A)
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 main or power relay contacts and if it has continuity,
replace main or 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 membrane
(CM1029)
key pad to Ass'y PCB
3. Shorted or open membrane panel
4. Defective Ass'y PCB
Replace PCB main.
1. Open or loose connection of high voltage
Adjust door and latch switches.
circuit especially magnetron filament
circuit
NOTE: Large contact resistance will bring
lower magnetron filament voltage and
Timer starts countdown
cause magnetron to lower output and/or
but no microwave
intermittent oscillation.
oscillation.
2. Defective high voltage components
Check high voltage component
(No heat while oven lamp
H.V.Transformer
according to component test procedure
and fan motor turn on.)
H.V.Capacitor
and replace if defective.
H.V.Diode, H.V.Fuse
Magnetron
