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R-21JCA-F

18

1. Precautions for Handling Electronic Components

This unit uses CMOS LSI in the integral part of the circuits.
When handling these parts, the following precautions should
be strictly followed. CMOS LSI have extremely high
impedance at its input and output terminals. For this reason,
it is easily influenced by the surrounding high voltage power
source, static electricity charge in clothes, etc., and
sometimes it is not fully protected by the built-in protection
circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap them in

aluminium foil. Also wrap PW boards containing them in
aluminium foil.

2) When soldering, ground the technician as shown in the

figure and use grounded soldering iron and work table.

2. Servicing of Touch Control Panel

We describe the procedures to permit servicing of the touch
control panel of the microwave oven and the precautions
you must take when doing so. To perform the servicing,
power to the touch control panel is available either from the
power line of the oven itself or from an external power
source.

(1) Servicing the touch control panel with power supply of

the oven :

CAUTION:
THE HIGH VOLTAGE TRANSFORMER OF THE MICRO-
WAVE OVEN IS STILL LIVE DURING SERVICING AND
PRESENTS A HAZARD .

Therefore, before checking the performance of the touch
control panel,

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 these leads remain isolated from other

components and oven chassis by using insulation
tape.

6) After that procedure, re-connect the power supply

cord.

After checking the performance of the touch control
panel,
1) Disconnect the power supply cord.
2) Open the door and block it open.
3) Re-connect the leads to the primary of the power

transformer.

4) Re-install the outer case (cabinet).
5) Re-connect the power supply cord after the outer

case is installed.

6) Run the oven and check all functions.

A.

 On some models, the power supply cord between the touch

control panel and the oven itself is so short that the two can't
be separated. For those models, check and repair all the
controls (sensor-related ones included) of the touch control

approx. 1M ohm

TOUCH CONTROL PANEL SERVICING

panel while keeping it connected to the oven.

B.

 On some models, the power supply cord between the touch

control panel and the oven proper is so long enough that
they may be separated from each other. For those models,
therefore, it is possible to check and repair the controls of
the touch control panel while keeping it apart from the oven
proper; in this case you must short both ends of the door
sensing switch (on PWB) of the touch control panel with a
jumper, which brings about an operational state that is
equivalent to the oven door being closed. As for the sensor-
related controls of the touch control panel, checking them is
possible if the dummy resistor(s) with resistance equal to
that of the controls are used.

(2) Servicing the touch control panel with power supply

from an external power source:

Disconnect the touch control panel completely from the
oven proper, and short both ends of the door sensing switch
(on PWB) of the touch control panel, which brings about an
operational state that is equivalent to the oven door being
closed. Connect an external power source to the power
input terminal of the touch control panel, then it is possible
to check and repair the controls of the touch control panel;
it is also possible to check the sensor-related controls of the
touch control panel by using the dummy resistor(s).

3. Servicing Tools

Tools required to service the touch control panel assembly.
1) Soldering iron: 60W

(It is recommended to use a soldering iron with a
grounding terminal.)

2) Oscilloscope: Single beam, frequency range: DC -

10MHz type or more advanced model.

3) Others: Hand tools

4. Other Precautions

1) Before turning on the power source of the control unit,

remove the aluminium foil applied for preventing static
electricity.

2) Connect the connector of the key unit to the control unit

being sure that the lead wires are not twisted.

3) After aluminium foil is removed, be careful that abnormal

voltage due to static electricity etc. is not applied to the
input or output terminals.

4) Attach connectors, electrolytic capacitors, etc. to PWB,

making sure that all connections are tight.

5) Be sure to use specified components where high

precision is required.

Summary of Contents for R-21JCA-F

Page 1: ... INFORMATION 4 OPERATION 6 TROUBLESHOOTING GUIDE 9 TEST PROCEDURE 10 TOUCH CONTROL PANEL 16 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE 20 PICTORIAL DIAGRAM 27 CONTROL PANEL CIRCUIT 28 PRINTED WIRING BOARD 29 PARTS LIST 30 PACKING AND ACCESSORIES 34 S0514R21JCPAF R 21JCA F LIGHT DUTY COMMERCIAL MICROWAVE OVENS MODEL SERVICE MANUAL SHARP CORPORATION This document has been published to be used fo...

Page 2: ...smission systems shall be repaired replaced or adjusted by procedures described in this manual before the oven is released to the owner e A microwave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven prior to release oven to the owner BEFORE SERVICING Before servicing an operative unit perform a microwave emission check as per the Microwave M...

Page 3: ...pacitor 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 Reconne...

Page 4: ...he oven cavity The water container shall be a low form of 600 ml 20 oz beaker with an inside diameter of approx 8 5 cm 3 1 2 in and made of an electrically nonconductive material such as glass or plastic The placing of this standard load in the oven is important not only to protect the oven but also to insure that any leakage is measured accurately 4 Set the cooking control on Full Power Cooking M...

Page 5: ...is not damaged D The door is not deformed or warped E There is no other visible damage with the oven Servicing and repair work must be carried out only by trained service personnel DANGER Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing Service person nel Do not contact the following parts while the appliance is energized High Voltag...

Page 6: ...e wire for the electric current WARNING Improper use of the grounding plug can result in a risk of electric shock Electrical Requirements The electrical requirements are a 120 volt 60 Hz AC only 15 amp or more protected electrical supply It is recommended that a separate circuit serving only this appliance be provided When installing this appliance observe all applicable codes and ordinances A sho...

Page 7: ...ter case cabinet 1 14 13 9 12 11 7 6 5 15 16 10 3 2 4 8 CONTROL PANEL TIME GUIDE FOR ONE SERVING 15 30 sec Bagel Roll Muffin Pastry Pie Slice 30 60 sec Hot Dog Pizza Slice Small Sandwich 1 2 min Beverage Soup Large Sandwich Popcorn 1 5 oz 2 3 min Casserole Stew Chili Chowder Popcorn 3 5 oz With the door closed turn the timer to the desired time Oven will begin operating immediately To shut oven of...

Page 8: ...tion of the cooking time the power transformer oven lamp etc are turned off and the generation of microwave energy is stopped The oven will revert to the OFF condition 6 When the door is opened during a cook cycle monitor switch door sensing switch secondary interlock switch relay RY2 and primary interlock relay RY1 are activated with the following results The circuits to the antenna motor the coo...

Page 9: ...OTOR POWER TRANSFORMER CAPACITOR 0 94 µF 2400V DOOR SENSING SWITCH SECONDARY INTERLOCK SWITCH CONTROL UNIT THERMAL CUT OUT 125 C OVEN THERMAL CUT OUT 145 C MAG PRIMARY INTERLOCK RELAY COOK RELAY MONITOR SWITCH MAGNETRON RECTIFIER RY1 RY2 A5 A3 A1 FUSE LINE CROSS CAPACITOR 0 22 F AC250V NOISE SUPPRESSION COIL LINE BYPASS CAPACITOR 0 003300 F AC 125V LINE BYPASS CAPACITOR 0 003300 F AC 125V 20A NOIS...

Page 10: ...ad Latch Head Handle Lever Door Handle Latch Lever Secondary Interlock Switch Monitor Switch Door Sensing Switch and secondary interlock switch contacts fail to open the monitor fuse blows simultaneously with closing of the monitor switch contacts CAUTION BEFORE REPLACING A BLOWN MONITOR FUSE TEST THE DOOR SENSING SWITCH PRIMARY INTERLOCK RELAY RY1 SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH FOR...

Page 11: ...tion 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...

Page 12: ... the water 2 Place the cup of water in the oven Operate oven at POWER 10 HIGH selecting more than 60 seconds cook time Allow the water to heat for 60 seconds measuring with a stop watch second hand of a watch or the digital read out countdown 3 Remove the cup from the oven and again measure the temperature making sure to stir the thermometer or thermocouple through the water until the maximum temp...

Page 13: ...omponents during testing 6 Reinstall the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all functions E THERMAL CUT OUT TEST 125 C OVEN 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 A continuity check across the thermal cut out terminals should ind...

Page 14: ...the door and block it open 3 Discharge high voltage capacitor 4 Disconnect two 2 wire leads from the male tab terminals of the Primary Interlock Relay Check the state of the relay contacts using a ohmmeter The relay contacts should be open If the relay contacts are closed replace the circuit board entirely or the relay itself 5 Reconnect all leads removed from components during testing 6 Reinstall...

Page 15: ...RY INTERLOCK RELAY SECONDARY INTERLOCK SWITCH DOOR SENSING SWITCH AND MONITOR SWITCH FOR PROPER OPERATION If the monitor fuse is blown by improper switch operation the monitor fuse and monitor switch must be replaced with monitor fuse and monitor switch assembly part number FFS BA015WRK0 even if the monitor switch operates normally The monitor fuse and monitor switch assembly is comprised of a 20 ...

Page 16: ... leads to the primary of the power transformer 5 Ensure that these leads remain isolated from other components and oven chassis by using insulation tape 6 After that procedure re connect the power supply cord 7 Remove the outer case and check voltage between Pin No 5 of the 3 pin connector A and the common terminal of the relay RY1 on the control unit with an A C voltmeter The meter should indicat...

Page 17: ...given below if indicator does not light up after above check and repairs are finished 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 these leads remain isolated from other components and oven chassis by using insulation tape 6 After that p...

Page 18: ...5 Buzzer Circuit The buzzer is responsive to signals from the LSI to emit audible sounds completion sound 6 Door Sensing Switch A switch to tell the LSI if the door is open or closed 7 Relay Circuit To drive the magnetron fan motor antenna motor and light the oven lamp 8 Encoder The encoder generates the pulse signal and the pulse signal is sent to the LSI 9 Indicator Circuit Indicator elements ar...

Page 19: ...s the door open close information to LSI Door closed L level signal Door opened H level signal 19 21 AIN1 AIN3 IN Terminal to change functions according to the model Signal in accordance with the model in operation is applied to set up its function 22 P00 OUT Terminal not used 23 P01 OUT Magnetron high voltage circuit driving signal To turn on and off the cook relay RY2 In 100 power operation the ...

Page 20: ...he two can t be separated For those models check and repair all the controls sensor related ones included of the touch control approx 1M ohm TOUCH CONTROL PANEL SERVICING panel while keeping it connected to the oven B On some models the power supply cord between the touch control panel and the oven proper is so long enough that they may be separated from each other For those models therefore it is...

Page 21: ...and that the iron temperature is adjusted accordingly 3 Soldering As the melting point of lead free solder Sn Ag Cu is higher and has poorer wettability flow to prevent damage to the land of the PWB extreme care should be taken not to leave the bit in contact with the PWB for an extended period of time Remove the bit as soon as a good flow is achieved The high content of tin in lead free solder wi...

Page 22: ... 2 Visually check the door and cavity face plate for damage dents cracks signs of arcing etc Carry out any remedial work that is necessary before operat ing the oven Do not operate the oven if any of the following conditions exist 1 Door does not close firmly 2 Door hinge support or latch hook is damaged 3 The door gasket or seal is damaged 4 The door is bent or warped 5 There are defective parts ...

Page 23: ...ly remove four 4 screws holding magnetron to waveguide when removing the screws hold the magnetron to prevent it from falling 11 Remove the magnetron from the waveguide with care so the magnetron antenna is not hit by any metal object around the antenna CAUTION WHEN REPLACING THE MAGNETRON BE SURE THE R F GASKET IS IN PLACE AND THE MAGNETRON MOUNTING SCREWS ARE TIGHTENED SECURELY CONTROL PANEL ASS...

Page 24: ... the oven 9 Remove the fan blade from the fan motor shaft according to the following procedure 10 Hold the edge of the rotor of the fan motor by using a pair of groove joint pliers CAUTION Make sure that no metal pieces enter the gap between the rotor and the stator of the fan motor because the rotor is easily shaven by pliers and metal pieces may be produced Do not touch the pliers to the coil of...

Page 25: ...ecure latch hook with two 2 mounting screws to oven flange 4 Make sure that the monitor switch is operating properly and check continuity of the monitor circuit Refer to chapter Test Procedure and Adjustment procedure Figure C 3a Power Supply Cord Replacement Figure C 3b Power Supply Cord Replacement Power Supply Cord Chassis Support WHT RED L N Screw Green Wire Noise Filter White Wire Oven Cavity...

Page 26: ...Latch Switch Adjustments 13 Remove the two 2 screws holding the door handle and the latch angle assembly through the door frame 14 Now door handle is free LATCH HEADS REMOVAL 15 Remove the one 1 screw holding the latch angle assembly to the door frame 16 Remove the latch angle assembly together with the latch lever latch spring and the upper and lower latch heads from the door frame 17 Release the...

Page 27: ...a Refer to Figure C 8 7 Release the antenna holder from the one 1 tab of the oven cavity bottom plate 8 Remove the stirrer antenna assembly from the oven cavity bottom plate 9 Remove the antenna motor shaft from the hole of the oven cavity bottom plate 10 Now the antenna motor shaft is free Figure C 8 Antenna Motor Shaft Removal ANTENNA MOTOR SHAFT REPLACEMENT Upper Oven Hinge Upper Oven Hinge Low...

Page 28: ... the oven cavity bottom plate 7 Now the ceramic shelf is installed INSTALLATION OF CERAMIC SHELF WARNING Make sure that the rubber packing is not caught between the oven door and the oven cavity front plate to avoid possible exposure to excessive microwave energy Flat face Flat face To right wall of oven cavity To left wall of oven cavity Antenna motor shaft Antenna holder Stirrer antenna Stirrer ...

Page 29: ...ETRON H V CAPACITOR H V RECTIFIER POWER TRANSFORMER GRN POWER SUPPLY CORD COM WHT WHT ORG WHT WHT N C N O COM CONNECTOR ORG ORG WHT BLU BRN ANTENNA MOTOR MONMITOR SWITCH PRIMARY INTERLOCK RELAY WHT BLU BLU RED ORG RED ORG ORG 2 3 4 5 1 YLW PNK BLU CN A RY2 RY1 NEUTRAL HOT EARTH PNK YLW N O COM DOOR SENSING SWITCH SECONDARY INTERLOCK SWITCH NOTE Hot ORG wire must be connected to the terminal with b...

Page 30: ...V 60Hz N O OVEN LAMP ANTENNA MOTOR FAN MOTOR N O RY2 Q22 KRC105S RY1 D22 D20 D30 4 7K 47K R31 R30 C30 D21 R21 4 7K Q20 KRC101S 4 7K R22 C21 10µ 35V 0 1µ 50V C20 R20 4 7K Q21 KRA101S HZ11A3 x 3 ZD3 ZD2 ZD1 1W 510 x 2 R3 1W 1K KTC3198A HZ6C3 x 2 ZD5 ZD4 KTA1504 R6 4 7K HZ4C1 ZD6 4 7K R10 D11 D10 0 1µ 50V 27K Q40 KRC101S SP1 R41 1 5K R42 3 3K 27K 27K R40 4 7K 220µ 16V C5 J3 J5 6 2K J7 J6 4 7K J4 4 7K...

Page 31: ... JP2 C21 JP3 CNC Q1 E B JP14 JP20 JP18 JP9 JP19 JP7 ZD1 ZD5 ZD4 ZD2 ZD3 D10 D11 D20 D21 JP17 JP13 JP8 JP1 R3 SP1 CF1 JP16 JP15 JP32 JP25 1 2 3 4 5 6 8 9 10 11 12 13 14 7 JP35 JP37 LD8 LD9 LD10 LD11 LD12 LD13 LD14 LD15 LD16 LD17 LD18 LD19 LD20 LD1 LD2 LD3 LD4 LD5 LD6 LD7 SW1 JP29 JP24 JP27 JP28 JP33 JP26 D84 D83 D75 D79 D82 D85 B C A ZD6 R2 C5 C3 R1 C1 D1 D3 D4 D2 J1 D22 CNA VRS1 SW2 D30 WHA WHA R1...

Page 32: ... GCOVAA260WRP0 C P case 1 BA 3 3 TCAUAA076WRR0 User caution label 1 AB 3 4 JKNBKA606WRM0 Timer knob 1 AL 3 5 XEPS730P08XS0 Screw 3mm X 8mm 5 AB OVEN PARTS 4 1 FGLSPA062WRE0 Ceramic shelf 1 BL 4 2 Oven cavity Not a replaceable part 1 4 3 MLEVPA227WRF0 Latch switch lever A 1 AF 4 4 MLEVPA228WRF0 Latch switch lever B 1 AF 4 5 MLEVPA229WRF0 Latch switch lever C 1 AF 4 6 MSPRCA108WRE0 Latch lever sprin...

Page 33: ...XEPS740P25K00 Screw 4mm x 25mm 2 AC 5 1 18 PCUSUA508WRP0 Cushion 1 AC 5 2 GCOVHA407WRF0 Choke cover 1 AM 5 3 HBDGCA107WREZ Door badge 1 AL MISCELLANEOUS 6 1 TINSEA954WRRZ Instruction book 1 AM 6 1 FW VZC073WREZ Main wire harness 1 AX 6 3 TCAUAA166WRR0 DHHS caution label 1 AB 6 4 TCAUAA295WRRZ Monitor caution 1 AH 6 5 TCAUAA243WRR0 Earth caution 1 AC 6 6 TCAUAA245WRR0 Cover caution 1 AC 6 7 TLABMA5...

Page 34: ...4 35 4 39 7 11 7 11 2 5 4 7 1 1 4 6 4 6 7 7 4 30 4 24 4 24 2 4 4 10 6 8 2 1 4 14 4 20 7 1 4 8 2 3 7 8 7 11 4 11 1 14 1 2 4 29 4 20 4 22 4 34 7 3 4 25 7 3 7 1 1 4 6 3 6 6 1 12 1 4 4 24 4 36 7 1 7 9 7 8 7 2 1 7 7 1 1 6 2 4 4 17 4 41 2 2 4 13 4 12 4 31 7 11 7 10 4 26 4 26 4 2 4 19 4 23 4 21 4 21 4 21 4 1 7 6 7 13 7 13 7 13 4 9 4 32 4 18 4 16 1 10 1 9 4 28 6 5 x2 4 40 6 10 4 27 4 20 4 20 4 37 4 38 ...

Page 35: ... 2 3 3 3 2 1 3 2 3 1 3 5 3 5 3 4 Actual wire harness may be different from illustration 5 1 6 5 2 5 1 4 5 6 2 5 1 15 5 1 7 5 1 8 5 1 8 5 1 9 5 1 13 5 1 17 5 1 11 5 1 3 5 1 4 1 5 1 1 5 1 4 5 5 1 12 5 1 12 5 1 14 5 1 18 5 1 4 5 1 17 5 1 2 5 1 16 5 1 16 5 1 16 5 1 16 x4 x2 6 9 5 3 5 1 5 1 5 5 1 10 5 1 4 3 5 1 4 4 5 1 4 2 ...

Page 36: ... or by any means electronic me chanical photocopying recording or other wise without prior written permission of the publisher PACKING AND ACCESSORIES INSTRUCTION BOOK TOP PAD ASSEMBLY FPADBA385WRK0 BOTTOM PAD ASSEMBLY FPADBA386WRK0 WRAP COVER SSAKHA034WRE0 DOOR PROTECTION SHEET SPADPA204WRE0 PACKING CASE SPAKCD803WREZ Not Replaceable Items TRAY HOLDER SPADFA435WRE0 Into the Oven Cavity 6 1 MENU S...

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