6-1 Electrical Malfunction(continued)
SYMPTOM
CAUSE
CORRECTIONS
Oven lamp and fan motor turn on
1. Misadjustment or loose wiring
of secondary latch switch
2. Defective Secondary latch switch
Adjust door and latch switches.
Oven can program but timer
does not start.
1. Open or loose wiring of
secondary interlock switch
2. Off-alignment of Secondary
interlock
3. Defective secondary interlock S/W
Adjust door and interlock
switches.
Microwave output is low;.
Oven takes longer time to
cook food.
1. Decrease in power source
voltage.
2. Open or loose wiring of
magnetron filament circuit.
(Intermittent oscillation))
3. Aging of magnetron
Consult electrician.
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.
Defective Ass’y PCB
Replace PCB main.
Loud buzzing noise can be heard.
1. Loose fan and fan motor
2. Loose screws on
H.V.Transformer
3. Shorted H.V.Diode
Tighten screws of fan motor.
Tighten screws of
H.V.Transformer.
Replace H.V.Diode.
Turntable motor does not rotate.
1. Open or loose wiring of
turntable motor.
2. Defective turntable motor.
Replace turntable motor.
Oven stops operation during cooking
1. Open or loose wiring of
Secondary interlock switch
2. Operation of thermal
cutout(Magnetron)
Adjust door and latch switches.
Sparks
1. Metallic ware or cooking dishes
touching on the oven wall.
2. Ceramic ware trimmed with
gold or silver powder also
causes sparks.
Inform the customer.
Do not use any type of cookware
with
metallic trimming.
Uneven cooking
Uneven intensity of microwave due
to its characteristics.
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.
Noise from the turntable motor when
it starts to operate.
Noise may result from the motor.
Replace turntable motor.
