Troubleshooting guide, 1] troubleshooting chart, Chapter 7. troubleshooting guide – Sharp Carousel R-305KS User Manual

Page 13: Chart, Chapter 7, R305ks

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R305KS

7 – 1

R305KS

CHAPTER 7.

TROUBLESHOOTING GUIDE

Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.

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 monitor fuse,
check the monitor switch, primary interlock relay (RY2), door sensing
switch and secondary interlock switch before replacing the monitor
fuse. If monitor fuse is replaced, the monitor switch must also be
replaced. Use part FFS-BA037WRKZ as an assembly.

IMPORTANT

:

Whenever troubleshooting is performed with the power supply cord
disconnected. It may in, some cases, be necessary to connect the
power supply cord after the outer case has been removed, in this
event,

1) Disconnect the power supply cord, and then remove outer case.

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Disconnect the leads to the primary of the power transformer.

5) Ensure that the leads remain isolated from other components and

oven chassis by using insulation tape.

6) After that procedure, reconnect the power supply cord.

When the testing is completed,

1) Disconnect the power supply cord, and then remove outer case.

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Reconnect the leads to the primary of the power transformer.

5) Reinstall the outer case (cabinet).

6) Reconnect the power supply cord after the outer case is installed.

7) Run the oven and check all functions.

[1] TROUBLESHOOTING CHART

RE CK A

B

C

D

E

F

F

G

H RE RE CK J CK CK CK K

L

N

I

POSSIBLE CASE

AND DEFECTIVE PARTS

SHORT

IN

POWER

CORD

SHORT

OR

OPENED

WIRING

MAGNETRON

POWER

TRANSFORMER

H.V.

RECTIFIER

ASSEMBLY

HIGH

VOLTAGE

CAPACITOR

TEMPERATURE

FUSE

or

THERMAL

CUT-OUT

PRIMARY

INTERLOCK

S

YSTEM

SECONDARY

INTERLOCK

S

WIT

MONITOR

SWITCH

MONITOR

FUSE

OVEN

LAMP

COOLING

FAN

MOTOR

TURNTABLE

MOTOR

TOUCH

CONTROL

PANEL

WRONG

OPERATION

LOW

V

OLTAGE

DIRTY

O

VEN

CAVITY

KEY

UNIT

(MEMBRAINE

SWITCH

RELAY

(RY1)

FOIL

PATTERN

O

N

P

WB

NOISE

FILTER

CONDITION

PROBLEM

OFF

CONDITION

TTEST PROCEDURE

COOKING

CONDITION

M

DEFROST

Home fuse or circuit breaker blows when
power cord is plugged into wall receptacle

Monitor fuse blows when power cord is plug-
ged into wall receptacle.

All letters and indicators do not appear in dis-
play when power cord is first plugged into
wall outlet.

Display does not operate properly when
STOP/CLEAR key is touched. (Buzzer
should sound and ":" or time of day should
appear in display.)

Oven lamp does not light when door is
opened.

Oven lamp does not go out when door is
closed.

Oven lamp lights but fan motor and turntable
motor do not operate.

Oven does not go into cook cycle when
START pad is touched

Oven seems to be operating but little or no
heat is produced in oven load. (Food incom-
pletely cooked or not cooked at all at end of
cook cycle.)

Oven goes into a cook cycle but extremely
uneven heating is produced in oven load
(food).

Oven does not cook properly when program-
med for Cooking Power P-50 mode. (Oper-
ates properly on Cooking Power P-HI (HIGH)
mode.)

Oven goes into DEFROST but food is not
defrosted well.

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