12-1 Electrical Maltunction(continved)
SYMPTOM
Oven lamp and fan motor turn on
Oven can program but timer
does not start.
Microwave output is low;.
Oven takes longer time to
cook food.
Fan motor turns on when plugged in Loose wiring of door sensing switch Check wire of door sensing switch.
Oven does not operate and return to
the plugged in mode.
Loud buzzing noise can be heard.
Turntable motor does not rotate.
Oven stops operation during
cooking
Sparks
Uneven cooking
Noise from the turntable motor
when it starts to operate.
CAUSE
1. Misadjustment or loose wiring
of primary latch switch
2. Defective primary latch switch
1. Open or loose wiring of
secondary interlock switch
2. Off-alignment of primary
interlock
3. Defective secondary interlock S/W
1. Decrease in power source
voltage.
2. Open or loose wiring of
magnetron filament circuit.
(Intermittent oscillation))
3. Aging of magnetron
Defective Ass'y PCB
1. Loose fan and fan motor
2. Loose screws on
H.V.Transformer
3. Shorted H.V.Diode
1. Open or loose wiring of
turntable motor.
2. Defective turntable motor.
1. Open or loose wiring of primary
interlock switch
2. Operation of thermal
cutout(Magnetron)
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.
39
CORRECTIONS
Adjust door and latch switches.
Adjust door and interlock switches.
Consult electrician.
Replace PCB main.
Tighten screws of fan motor.
Tighten screws of H.V.Transformer.
Replace H.V.Diode.
Replace turntable motor.
Adjust door and latch switches.
Inform the customer.
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.