Sears 721. 63762, Field Manual

Page: 34 / 46

7-23
CONDITION CHECK RESULT CAUSE REMEDY
1. Setting time
does not count
down when
touching START
pad.
2. Fan motor or
oven lamp do
not turn on.
No continuity.
Continuity.
Continuity
Defective control
PCB assembly.
Loose connection.
Replace control
PCB assembly.
Connect them
tightly.
No continuity
Abnormal Check fan motor. Defective fan motor. Replace fan motor.
Abnormal
Normal
Check oven lamp.
Defective oven lamp. Replace oven lamp.
Defective
secondary switch. Replace
secondary switch.
Check continuity
of secondary
switch (with
door closed).
Check the con-
nection between
CN1 connector
and control PCB
assembly.
(TROUBLE 3) Display shows all figures set, but oven does not start cooking while desired
program times are set and START pad is touched.
3. The display
shows F-9.
No continuity.
Continuity.
Loose connection.
Connect them
tightly. Check the
connection between
magnetron, door &
control PCB and
inverter module.
Abnormal
Normal
Defective Relay2.
Replace control
PCB assembly. Check the Relay 2 of
control PCB assembly.
Check the
inverter module.
Abnormal
Normal
Defective inverter
module. Replace inverter
module.
Check the
Magnetron.
Abnormal
Defective
Magnetron. Replace
Magnetron.
Normal
Check the power
source voltage.
Abnormal
Unsafe AC input
voltage.
Suggest customer
contact local electric
power utility co. or
qualified electrician.