Samsung SMH9187W Service Manual page 25

Oven does not
accept key input
4. Troubleshooting
Timer starts countdown but no microwave oscillation .
(No heat while oven lamp and fan motor turn on.)
Timer starts
countdown but
no microwave
oscillation
Oven can program but timer does not start .
Oven can program
but timer does
not start
Oven can program
but timer does
not start
Oven can program
but timer does
Oven can program not start
Microwave output is low . (Oven takes longer time to cook food .)
but timer does
not start
Microwave
output is low
Microwave
output is low
Microwave
output is low
Microwave
output is low
Fan motor turns
on when plugged in
Fan motor turns on when plugged in .
Fan motor turns
on when plugged in
Fan motor turns
on when plugged in
Fan motor turns
Oven does not
on when plugged in
operate and return to
the plugged
Oven does not
in mode
operate and return to
Oven does not operate and return to the plugged in mode .
the plugged
Oven does not
in mode
operate and return to
Oven does not
the plugged
operate and return to in mode
Loud buzzing noise
the plugged
can be heard
in mode
Loud buzzing noise
can be heard
Loud buzzing noise
can be heard
Loud buzzing noise
can be heard
Turntable motor does
not rotate.
Open or loose connection of
membrane key pad to Ass'y PCB
Shorted or open membrane panel
Defective Ass'y PCB
Off-alignment of latch switches
Open or loose connection of high
voltage circuit especially magnetron
filament circuit
(NOTE)
Defective high voltage components
H.V.Transformer H.V. Capacitor
H.V.Diode, H.V.Fuse Magnetron
Open or loose wiring of power relay
Defective primary latch switch
Defective power relay or Ass'y PCB
NOTE: Large contact resistance will bring lower magnetron filament voltage and cause magnetron
to lower output and/or intermittent oscillation.
Open or loose wiring of secondary
interlock switch
Open or loose wiring of secondary
Off-alignment of primary interlock
interlock switch
Open or loose wiring of secondary
Defective secondary interlock S/W
Off-alignment of primary interlock
interlock switch
Open or loose wiring of secondary
interlock switch
Off-alignment of primary interlock
Defective secondary interlock S/W
Decrease in power source voltage
Off-alignment of primary interlock
Defective secondary interlock S/W
Open or loose wiring of magnetron
Decrease in power source voltage
filament circuit.
Defective secondary interlock S/W
(Intermittent oscillation)
Open or loose wiring of magnetron
Decrease in power source voltage
filament circuit.
Aging of magnetron
(Intermittent oscillation)
Decrease in power source voltage
Open or loose wiring of magnetron
filament circuit.
Aging of magnetron
Open or loose wiring of magnetron
(Intermittent oscillation)
filament circuit.
(Intermittent oscillation)
Aging of magnetron
Loose wiring of door sensing switch
Aging of magnetron
Loose wiring of door sensing switch
Loose wiring of door sensing switch
Loose wiring of door sensing switch
Defective Ass'y PCB
Defective Ass'y PCB
Defective Ass'y PCB
Loose fan and fan motor
Defective Ass'y PCB
Loose screws on H.V.Transformer
Loose fan and fan motor
Shorted H.V.Diode
Loose fan and fan motor Loose screws on H.V.Transformer
Loose fan and fan motor
Loose screws on H.V.Transformer
Shorted H.V.Diode
Loose screws on H.V.Transformer Open or loose wiring of
Shorted H.V.Diode
turntable motor.
25
Shorted H.V.Diode
Open or loose wiring of
Defective turntable motor
Replace PCB main.
Adjust door and latch switches.
Check high voltage component according to
component test procedure and replace if it is
defective.
Replace PCB main.
Adjust door and interlock switches.
Adjust door and interlock switches.
Adjust door and interlock switches.
Adjust door and interlock switches.
Consult electrician.
Consult electrician.
Consult electrician.
Consult electrician.
Consult electrician.
Consult electrician.
Consult electrician.
Consult electrician.
Replace PCB main.
Replace PCB main.
Replace PCB main.
Tighten screws of fan motor.
Replace PCB main.
Tighten screws of H.V.Transformer.
Tighten screws of fan motor.
Replace H.V.Diode.
Tighten screws of fan motor.
Tighten screws of H.V.Transformer.
Tighten screws of fan motor.
Tighten screws of H.V.Transformer.
Replace H.V.Diode.
Tighten screws of H.V.Transformer.
Replace turntable motor.
Replace H.V.Diode.
Replace H.V.Diode.
Replace turntable motor.