Samsung CM1929 Service Manual page 21

6. Troubleshooting
SYMPTOM
Oven lamp goes off
Microwave output is low; .
Oven takes longer time to
cook food .
(Noheat while oven lamp and
ventilation)
Oven does not operate and
return to the plugged in mode .
Loud buzzing noise can be
heard .
Drive motor not work .
(Ass'y stirrer dose not rotate .)
Oven stops operation during
cooking
Sparks
Uneven cooking
Noise from the turntable
motor when it starts to
operate .
Oven can program but timer
does not start .
CAUSE
1. Loose lead wire or open filament
2 . Misadjustment of latch switch
3 . Defactive primary latch switch
1 . Decrease in power source voltage .
2 . Open or loose wiring of magnetron
filament circuit.
(Intermittent oscillation))
3 . Aging of magnetron
4 . Defective high voltage compnents
H .V . Transfomer
H .V . Capacitor
H .V . Diode, H .V . Fuse
Magnetron
Defective Ass'y PCB
1 . Loose fan and fan motor
2 . Loose screws on H .V .Transformer
3 . Shorted H .V .Diode
4 . Loose or missing screw on Cover-
Back
1 . Open or loose wiring of turntable
motor .
2 . Defective turntable motor .
3 . Defective ass'y stirrer
1 .Operationofthermalcutout
(Magnetron or Cavity)
2 . Fan motor does not rotate .
1 . Metallic ware or cooking dishes
touching on the oven wall .
2 . Ceramic ware trimmed with gold or
silver powder also causes sparks .
Uneven intensity of microwave due to
its characteristics .
Noise may result from the motor .
Defective circuitry of Start function of
Main P .C .B Ass'y
Loose lead wires .
20
CORRECTIONS
Tighten lamp lead wire or replace with a
new lamp
Consult electrician .
Check high coltage component
according to component test procedure
and replace if defective
Replace PCB main .
Tighten screws of fan motor .
Tighten screws of H .V .Transformer .
Replace H .V .Diode .
Tighten screws of Cover-Back
Check the wire of drivemotor
Replace drive motor .
Replace ass'y stirrer .
Adjust door and latch switches .
Replace Fan motor .
Informthecustomerofproperuse .
Do not use any type of cookware with
metallic trimming .
Wrap thinner parts of the food with
aluminum foil .
Use plastic wrap or cover with a lid .
Stir once or twice while cooking
foods such as soup, cocoa, or milk .
Replace turntable motor .
Check circuitry of Start function of Main
P .C .B Ass'y and replace if defective .
Adjust od repair loose wires .