R-209 - Sharp Home Appliance Service Manual (repair manual). Page 8

6

CK = Check / RE = Replace

MAGNETRON

HIGH VOLTAGE TRANSFORMER

H.V. RECTIFIER ASSEMBLY

HIGH VOLTAGE WIRE

HIGH VOLTAGE CAPACITOR

MONITORED LATCH SWITCH 

LATCH

 SWITCH 

MONITOR SWITCH 

TEMPERATURE FUSE 

TIMER MOTOR

TIMER SWITCH

FAN MOTOR

TURNTABLE MOTOR

FUSE T6.3A

CONTROL UNIT

RELAY (RY-1)

FOIL PATERN ON P.W.B.

POWER SUPPLY CORD

SHORTED WIRE HARNESS

OPENED WIRE HARNESS

OVEN LAMP

WALL OUTLET

MISADJUSTMENT SWITCH

HOME FUSE OR BREAKER

BLOCKED COOLING FAN

BLOCKED VENTILATION

NOISE FILTER

H.V. FUSE

Home fuse blows when power
supply cord is plugged into
wall outlet.

FUSE T6.3A blows when
power supply cord is plugged
into wall outlet.

Oven does not start when the
timer is set.

Oven lamp does not light
(Other function is normal.)

Fan motor does not operate.
(Other function is normal.)

Turntable motor does not op-
erate. (Other function is nor-
mal.)

Oven or any electrical parts
does not stop.

Oven seems to be operating
but little or no heat is produced
in oven load. (Microwave
power level is set at HIGH.)

Oven does not seems to be
operating properly when MED
HIGH, MED, MED LOW or
LOW is set. (Oven operates
properly at HIGH.)

Oven goes into cook cycle but
shuts down before end of cook-
ing cycle.

OFF
CONDITION

PROBLEM

CONDITION

POSSIBLE CAUSE

AND

DEFECTIVE PARTS

TEST PROCEDURE

ON
CONDITION

A B C

CK

D E E E     F K   K   I   I   G   L M N

RE CKCKRECK CKCKCK CK

H J

When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks.
Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure
letter which will be found in the “Test Procedure” section.

IMPORTANT: If the oven becomes inoperative because of a blown fuse  T6.3A in the monitored latch switch  - timer

switch  - monitor switch circuit, check the monitored latch switch , timer switch and monitor switch  before
replacing the fuse  T6.3A.