Read Sharp R-291KM Service Manual online
R-291(K)M
7 – 1
R218L(W)
CHAPTER 7.
TROUBLESHOOTING GUIDE
[1] FOREWORD
When troubleshooting the microwave oven, it is helpful to follow the
Sequence of Operation in performing the checks. Many of the possible
Sequence of Operation in performing the checks. Many of the possible
tests are given a procedure letter which will be found in the “Test Pro-
cedure” section.
cedure” section.
IMPORTANT:
If the oven becomes inoper ative because of a blown fuse T6.3A in the
monitored latch switch - relay RY1 - timer switch - monitor switch cir-
cuit, check the monitored latch switch, relay RY1, timer switch and
monitor switch before replacing the fuse T6.3A.
monitored latch switch - relay RY1 - timer switch - monitor switch cir-
cuit, check the monitored latch switch, relay RY1, timer switch and
monitor switch before replacing the fuse T6.3A.
[2] CHART
HUMIDITY SENSOR
NOISE FILTER
SENSOR
COOKING
CONDITION
COOKING
CONDITION
Humidity sensor does not end
during Sensor cooking condition.
(Oven doesnot shut off after a
cup of water is boiling by sen-
sor cooking.)
during Sensor cooking condition.
(Oven doesnot shut off after a
cup of water is boiling by sen-
sor cooking.)
Oven stops at 16 sec. after
starting.
starting.
N
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DOOR SENSING SWITCH
SECONDARY INTERLOCK SWITCH
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OFF
CONDITION
CONDITION
PROBLEM
CONDITION
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
TEST PROCEDURE
ON
CONDITION
CONDITION
A B C
CK
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RE CK CK RE CK CK CK CK CK
Home fuse blows when power
supply cord is plugged into
wall outlet.
FUSE T6.3A blows when
FUSE T6.3A blows when
power supply cord is plug-
ged into wall outlet.
"88:88" does not appear in
display but power supply cord
is plugged into wall outlet.
Display does not operate
display but power supply cord
is plugged into wall outlet.
Display does not operate
properly when STOP/CLEAR
pad is touched.
Oven does not start when
Oven does not start when
the START pad is touched.
(Display appears)
Oven lamp does not light
Oven lamp does not light
(Display appears.)
Fan motor does not operate.
Fan motor does not operate.
(Display appears.)
Turntable motor does not
Turntable motor does not
operate. (Display appears.)
Oven or any electrical parts
Oven or any electrical parts
does not stop when cooking
time is 0 or STOP/CLEAR
pad is touched.
Oven seems to be operating
Oven seems to be operating
but little or no heat is pro-
duced in oven load. (Micro-
wave power level is set at
HIGH)
Oven does not seems to be
Oven does not seems to be
operating
properly
when
70%,50%, 30% or 10% is
set. (Oven operates properly
at 100%.)
Oven goes into cook cycle
Oven goes into cook cycle
but shuts down before end
of cooking cycle.
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