Sharp R308jsf Service Manual

R-308JK
R-308JS
R- 308JW
R- 309JW
In the interest of user-safety the oven should be restored to its origin\
al
condition and only parts identical to those specified should be used.
WARNING TO SERVICE PERSONNEL: Microwave ovens contain
circuitry capable of producing very high voltage and current,
contact with following parts may result in a severe, possibly fatal,
electrical shock. (High Voltage Capacitor, High Voltage Power
Transformer, Magnetron, High Voltage Rectifier Assembly,  High
Voltage Harness...

R-308JK
R-308JS
R-308JW
R-309JW
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE
ENERGY
(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other
microwave source, and make repairs as necessary: (1) interlock operation, (2) proper door closing, (3)
seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or...

R-308JK
R-308JS
R-308JW
R-309JW
1
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of pro-
ducing very high voltage and current, contact with
following parts 
 may result in a severe, possibly
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Trans-
former, Magnetron, High Voltage Rectifier Assem-
bly,  High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
Before Servicing
1. Disconnect the power supply cord          ,...

R-308JK
R-308JS
R-308JW
R-309JW
2
MICROWAVE MEASUREMENT PROCEDURE
A. Requirements:
1)Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should
not exceed 1mW/cm
2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a
purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface
of the oven.
2) Safety interlock switches:
 Primary...

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R-308JS
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R-309JW
3
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
SERVICE MANUAL
MICROWAVE OVEN
R-308JK/ R-308JS/ R-308JW/ R-309JW
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the SHARP
MICROWAVE OVENS,R-308JK, R-308JS, R-308JW and R-309JW.
It is recommended that service personnel carefully study the entire text of
this manual so that they will be qualified to render...

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R- 308JS
R- 308JW
R- 309JW
4
ITEM DESCRIPTION
Power Requirements 120 Volts / 13.5 Amperes
60 Hertz
Single phase, 3 wire grounded
Power Output 1100 watts (IEC TEST PROCEDURE)
Operating frequency of 2450MHz
Case Dimensions Width 20-1/2 Height 12-1/4
Depth  17-3/8
Cooking Cavity Dimensions Width 14-1/2 Height 8-1/8
1.0 Cubic Feet Depth  15-1/4
Control Complement Touch Control SystemClock ( 1:00 - 12:59 )
Timer (0 - 99 min. 99 seconds)
Microwave Power for Variable Cooking
  Repetition Rate;P-HI...

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5
properly grounded and polarized. If the extension cord must be used, it
should be a 3-wire, 15 amp. or higher rated cord. Do not drape over a
countertop or table where it can be pulled on by children or tripped ove\
r
accidentally.
CAUTION: DO 
NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE
THE ROUND GROUNDING PRONG FROM THIS PLUG.
OVEN DIAGRAM
1 Door opening button
Push to open door.
2 Oven door with see-through window
3 Safety door latches
The oven will not operate unless...

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OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and second-
ary interlock switch. (In this condition, the monitor switch
contacts are opened.)
When oven is plugged in, 120 volts A.C. is supplied to the
control unit. (Figure O-1).
1. The display will show flashing 88:88.
To set any program or set the clock, you must first touch
the...

R-308JK
R-308JS
R-308JW
R-309JW
7 Figure O-1. Oven Schematic-Off Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. CLOCK APPEARS ON DISPLAY
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. COOKING TIME PROGRAMMED
3. VARIABLE COOKING CONTROL P-HI (100%)
4. START PAD TOUCHED
Figure O-2. Oven Schematic-Cooking Condition
NOTE:     indicates components with potential above 250V.
120V AC
60 Hz
OVEN
LAMP
OVEN LAMP
RELAY
TURN-
TABLE
MOTORFAN 
MOTORPOWER 
TRANSFORMERMONITOR 
SWITCH
RECTIFIER...

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DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the control
panel, refer to the Figure D-1.
When the open button is pushed, the open button pushes up
the switch lever, and then the switch lever pushes up the latch
head. The latch heads are moved upward and released from
latch hook. Now the door will open.
Figure D-1. Door Open Mechanism
DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The secondary interlock switch...