R-216 (serv.man2). Complete - Sharp Home Appliance Service Manual (repair manual). Page 8

6

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

MAGNETRON

HIGH VOLTAGE TRANSFORMER

H.V. RECTIFIER ASSEMBLY

HIGH VOLTAGE WIRE

HIGH VOLTAGE CAPACITOR

MONITORED  LATCH SWITCH

2ND. INTERLOCK RELAY CONTROL SWITCH

MONITOR SWITCH

THERMAL CUT-OUT 125˚C (OVEN)

THERMAL CUT-OUT 95˚C (MG)

FAN MOTOR

TURNTABLE MOTOR

FUSE T6.3A

CONTROL PANEL

TACT SWITCH

RELAY 

RY1,

RELAY 

RY2,

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 when cooking
time is 0.

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
MEDIUM HIGH, MEDIUM,
MEDIUM LOW or LOW is set.
(Oven operates properly at
HIGH.)

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

Oven lamp, turntable motor
and fan motor do not operate.

The microwave power level can
not be changed.

OFF
CONDITION

PROBLEM

CONDITION

POSSIBLE CAUSE

AND

DEFECTIVE PARTS

TEST PROCEDURE

ON
CONDITION

CK = Check / RE = Replace

A B C

CK

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

RECKCKRE CKCKCK CK CK

I J