LG LMVM1945SW - Low Heat Output Troubleshooting

7-24
(TROUBLE 4) Oven seems to be operating but little heat is produced in oven load.
NOTE : Simple test of power output-conducted by heating one liter water for one min. if available.
Minimum 8.5°C temperature rise is normal condition.
CONDITION CHECK RESULT CAUSE REMEDY
Output is low
Lower than 90% of
rating voltage.
Normal
Defective
Magnetron.
Replace
Magnetron.
Decrease in power
source voltage
with load.
Suggest customer
contact local
electric power
utility co. or
qualified
electrician.
Check the
power source
voltage.
CONDITION CHECK RESULT CAUSE REMEDY
4. The display
shows F-4.
Abnormal
Normal
Loose connection.
Connect them
tightly.
Check the
connection between
sensor wire and
control PCB.
Abnormal
Normal
Defective sensor . Replace sensor.
Check the sensor .
Defective door or
control PCB
assembly.
Replace door or
control PCB
assembly.