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QT-CD121

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CONTENTS

Page

IMPORTANT SERVICE NOTES ........................................................................................................................................  2
SPECIFICATIONS .............................................................................................................................................................  2
NAMES OF PARTS ...........................................................................................................................................................  3
REMOTE CONTROL .........................................................................................................................................................  3
DISASSEMBLY ..................................................................................................................................................................  4
REMOVING AND REINSTALLING THE MAIN PARTS .....................................................................................................  5
ADJUSTMENT ...................................................................................................................................................................  6
BLOCK DIAGRAM .............................................................................................................................................................  8
SCHEMATIC DIAGRAM / WIRING SIDE OF P.W.BOARD .............................................................................................  10
NOTES ON SCHEMATIC DIAGRAM ..............................................................................................................................  16
TYPES OF TRANSISTOR ...............................................................................................................................................  16
WAVEFORMS OF CD CIRCUIT ......................................................................................................................................  17
TROUBLESHOOTING .....................................................................................................................................................  18
FUNCTION TABLE OF IC ................................................................................................................................................  21
PARTS GUIDE/EXPLODED VIEW
PACKING OF THE SET

• In the interests of user-safety the set should be restored to its

original condition and only parts identical to those specified should
be used.

QT-CD121

SERVICE MANUAL

SHARP  CORPORATION

No. S5831QTCD121/

This document has been published to be used
for after sales service only.
The contents are subject to change without notice.

Summary of Contents for QT-CD121

Page 1: ...6 TYPES OF TRANSISTOR 16 WAVEFORMS OF CD CIRCUIT 17 TROUBLESHOOTING 18 FUNCTION TABLE OF IC 21 PARTS GUIDE EXPLODED VIEW PACKING OF THE SET In the interests of user safety the set should be restored to its original condition and only parts identical to those specified should be used QT CD121 SERVICE MANUAL SHARP CORPORATION No S5831QTCD121 This document has been published to be used for after sale...

Page 2: ...tor IMPORTANT SERVICE NOTES AllcheckmustberepeatedwiththeAClinecordplugconnection reversed Any reading of 0 3 volt RMS this corresponds to 0 2 milliamp AC or more is excessive and indicates a potential shock hazard which must be corrected before returning the audio product to the owner TO EXPOSED METAL PARTS CONNECT TO KNOWN EARTH GROUND TEST PROBE 0 15 µ F 1 5k ohms 10W VTVM AC SCALE SPECIFICATIO...

Page 3: ...Compartment 23 AC Power Input Socket 24 Headphones Socket 1 CD Track Down Review Button 2 CD Pause Button 3 CD Play Repeat Button 4 CD Track Up Cue Button 5 CD Stop Button 1 2 3 4 5 Remote Sensor 8 20 0 2 m 6 m 0 2 m 6 m 15 15 Notes concerning use Replace the batteries if control distance de creases or operation becomes erratic Periodically clean the transmitter LED on the remote control and the s...

Page 4: ...the wall outlet before starting to disassemble the unit 3 Take off nylon bands or wire holders where they need be removed when disassembling the unit After servicing the unit be sure to rearrange the leads where they were before disassembling 4 Take suffcient care on static electricity of integrated circuits and other circuits when servicing STEP REMOVAL PROCEDURE FIGURE Figure 4 4 Figure 4 3 Figu...

Page 5: ...nism How to remove the pickup See Fig 5 1 Remove the screws A1 x 2 pcs to remove the shaft A2 x1 pc 2 Remove the stop washer A3 x1 pc to remove the gear A4 x 1 pc 3 Remove the pickup Figure 5 REMOVING AND REINSTALLING THE MAIN PARTS A1 x2 2 6 x6mm Stop Washer A3 x1 CD Mechanism Gear A4 x1 Shaft A2 x1 Pickup ...

Page 6: ...ad resistance 8 ohms AM IF RF IF T3 Input Antenna Output Pin 19 of IC2 Band Coverage fL L4 Input Antenna fH TC4 Output Speaker Tracking 600 kHz L3 Terminal CNP201 1 400 kHz TC3 Load resistance 8 ohms Test Stage Specified Value Adjusting Point Instrument Connection VCO Frequency Specified Value Instrument Connection VR1 76 kHz 200 Hz Pin 13 pin 21 and ground of IC2 Adjusting Point Note After prepar...

Page 7: ...er will simply be turned on at first b If the laser is lit and the PLAY button is pressed again playback will start from the current pickup position c If the STOP button is pressed playback will stop When pressed again the laser will be turned off a Each time the PAUSE button is pressed during playback the tracking servo will be turned on or off Note If the PLAY button is pressed while in the stop...

Page 8: ... REMOTE RX771 57 24 27 28 31 60 41 44 30 33 22 23 37 CD LCD LCD701 PICKUP IN PU IN SW 19 13 14 SL SL 7 4V CD 1 2 3 4 5 6 GND A R CH L CH GND D POWER GND 7 4V D SECTION MAIN TO VVDD XIN XOUT VDD XVDD EFMO EFMIN CLV CLV V P HFL TES TOFF JP JP TGL RES CQCK COIN SQOUT RWC WRQ LCHO LC78622E IC802 SERVO SIGNAL CONTROL 16 93MHz XL801 SLI SLC CV JP DRF CE DAT CL CLK THLD DEF SLD SLEO SPO FD TO SL SL F E F...

Page 9: ... L CH SPEAKERS SP502 R CH SO651 SW201 C POWER FUNCTION AM FM SELECT B FM B SW201 D POWER FUNCTION RADIO TAPE REC POWER FUNCTION SW201 A B CD EC PB SW102 A F P B REC IC101 EQULIZER AMP BA331IL REC REC P B P B P B L R L R SW102 REC PB B D REC PB SW102 C E L CH REC PB HEAD R CH AUDIO GND 7 4V B2 DIGITAL GND POWER GND FROM CD SECTION R CH ERASE HEAD SW102 H REC PB BIAS OSC C201 L201 SW102 G REC PB B1 ...

Page 10: ...1 1 2 4 1 RES CQCK CO IN RWC SL SL DRF SQOUT WRQ PU IN DIGITAL GND 5V B B B B B SEG12 SEG11 SEG10 SEG9 SEG8 SEG7 SEG6 SEG5 SEG4 SEG3 SEG2 SEG1 SEG0 P00 P01 P02 P10 POWER IN D1 MUTE D4 COCK D3 RES D5 COIN D6 RWC D7 SL D8 SL DFR P20 SQOUT P21 WRQ P22 PU IN P23 RESET XIN XOUT VSS VDD XCOUT XCIN AVSS VREF P30 P31 P32 P33 P3P40 AIN5 SIMUKE AIN6 KIDSW AIN7 VLC3 VLC2 VLC1 COM3 COM2 COM1 COM0 SEG16 VCC1 L...

Page 11: ...5 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 1 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 15 16 33 34 33 34 35 36 37 38 39 41 40 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 47 48 0V 3 5V 3 5V 2 5V 2 5V 7 4V 7 4V 0V 0V 2 7V 3 8V 3 2V 3 5V 3 5V 2 5V 0V 0V 0V 0V 2 5V 2 5V 3 8V 3 2V 0V 4 8V 7 4V 5 5V B AUDIO GND POWER GND DIGITAL...

Page 12: ...C15 0 022 IC2 LA1805 VC4 TC4 C17 0 022 C21 0 022 C20 0 022 T3 CF2 C26 22 16 SW201 A CD R16 2 2K R13 3 9K R14 3 9K R15 2 2K C33 1 50 C34 1 50 R38 1 8K 0 022 C32 C31 0 022 R17 68 C36 0 022 R121 1 5K D103 1N4148 R122 1 5K C123 100 10 C121 0 01 C122 0 01 D101 1N4148 D102 1N4148 R120 3 3K R119 3 3K C119 2 2 50 C120 47 16 R125 680K R118 3 9K C115 0 018 ML C117 10 16 R117 3 9K R115 3 9K R113 8 2K C118 10...

Page 13: ...D651 1N4004 D652 1N4004 C652 0 022 C653 0 022 D654 1N4004 D653 1N4004 T601 POWER TRANSFOMER SO651 CNP602 CNS602 R222 1K R221 1K R227 120 C219 0 047 ML C220 0 047 ML C216 0 039 ML C215 0 039 ML 3 2 1 1 2 3 4 5 6 7 8 9 10 11 12 13 M 1 2 3 1 2 3 1 2 2 R228 120 J201 HEADPHONES R213 22K R214 22K R205 4 7K C205 0 0018 C206 0 0018 R204 10K R203 10K R209 22K C207 4 7 50 R210 22K R206 4 7K B B B BATTERYS D...

Page 14: ...R103 R120 R114 R106 R354 1 2 R353 R352 R122 IC802 SW102 CNP101 IC101 IC202 FW701 CNP201 LCD701 1 2 3 4 5 6 7 8 BI801 C227 L301 CNP602 IC203 SW774 SW773 SW772 STOP SW771 PLAY VR201 1 7 29 30 8 14 15 21 22 28 IC804 C807 C35 C27 C34 C15 C14 C29 C11 C36 C22 C24 C25 C23 C37 C8 C5 C6 C33 C32 C17 C20 C26 C21 C837 C845 C850 C840 C802 C801 C803 C804 C806 C814 C812 C816 C832 C741 Q740 Q805 CF1 C38 C10 C39 C...

Page 15: ... 1 BR COLOR TABLE RD R OR YL GR BL VL GY WH W BK PK BROWN RED ORANGE YELLOW GREEN BLUE VIOLET GRAY WHITE BLACK PINK T601 POWER TRANSFORMER 236 211 BATTERYS DC12V D SIZE UM SUM 1 R20 or HP2 battery 8 YL TAPE MOTOR 241 6 M601 TAPE MAIN 241 7 SW601 CNS201 1 2 3 WH BK RD 2 1 SPENDLE MOTOR PICKUP IN M701 SLED MOTOR M702 CNP803 SW702 1 2 3 4 5 6 5 4 3 2 1 7 8 6 5 4 3 2 1 PICK UP UNIT CD MOTOR PWB B TERM...

Page 16: ...bol is an ohm resistor The resistor designated Fusible is a fuse type resistor Capacitor To indicate the unit of capacitor a symbol P is used this symbolPmeansmicro micro faradandtheunitofthecapacitor withoutsuchasymbolismicrofarad Astoelectrolyticcapacitor the expression capacitance withstand voltage is used CH TH RH UJ Temperature compensation ML Mylar type P P Polypropylene type The indicated v...

Page 17: ...0 V JP 0 5ms 10 0 V JP 0 5ms 0 50 V JP 0 5ms 1 00 V TE 6 7 9 8 6 7 9 8 50ms 10 0 V JP CUE 50ms 10 0 V JP 50ms 0 50 V JP 50ms 1 00 V TE 6 7 9 8 6 7 9 8 11 10 11 10 12 12 REVIEW 50ms 10 0 V JP 50ms 10 0 V JP 50ms 0 50 V JP 50ms 1 00 V TE 0 5ms 10 0 V JP 0 5ms 10 0 V JP 0 5ms 0 50 V JP 0 5ms 1 00 V TE PLAY 20ms 1 00 V SPO NORMAL DISC TN0 01 20ms 2 00 V CLV PLAY TCD 712 140mm TN0 01 50ms 1 00 V SPO 50...

Page 18: ...f isopropyl alcohol Do not touch the lens with the bare hand See if the pick up is in the pick up in SW702 position If the items mentioned above are OK check the main microcomputer IC701 Yes Yes The CD function will not work The CD operating keys don t work Check the CD DPS microcomputer IC701 power supply 4 19 MHz and 16 93 MHz clock and reset terminal Check the waveform of SCK SO DATA and SI COM...

Page 19: ...µsec DIV DC When playing back the disc Waveform in case of normal play back 3 2 1 4 0 5s 1 00 V IC801 16 FD 0 5s 10 0 V IC801 12 CLV 0 5s 10 0 V IC801 54 DRF 0 5s 2 00 V IC801 7 TE Check the tracking system Check the tracking system Check waveform of IC801 pin 7 TE Check the periphery of IC801 pin 8 to pin 15 and IC804 to BI801 CNS801 Tracking servo is inoperative The waveform shown in Fig 19 3 ap...

Page 20: ...10 Error Yes Check PDO waveform Fig 20 Checking the VCO PLL system Play operation is performed when disc exits Yes Although HF waveform is normal TOC data cannot be read Figure 20 2 3 0 5s 1 00 V IC802 3 PDO 0 5s 1 00 V IC801 16 FD As VCO freque ncy is locked at 4 32 M Hz voltage of PDO rises and stabili zes Stop Play Check IC802 pins 37and 40 Check the periphery of IC803 OPAMP Abnomal Usually the...

Page 21: ...d 17 P20 DRF Input Output Used to receive 4 bits at a time 18 P21 SQOUT Input Output Used to receive 4 bits at a time 19 P22 WRQ Input Output Used to receive 4 bits at a time 20 P23 PU IN Input Output Used to receive 4 bits at a time 21 RESET Input Output Reset pulse input output terminal When a reset is caused by the watch dog timer an L level will be output The output is an N channel open drain ...

Page 22: ...QT CD121 22 M E M O ...

Page 23: ... VCT Semiconductor type VC MF Cylindrical type without lead wire VC MN Cylindrical type without lead wire VC TV Square type without lead wire VC TQ Square type without lead wire VC CY Square type without lead wire VC CZ Square type without lead wire VC J The 13th character represents capacity difference J 5 K 10 M 20 N 30 C 0 25 pF D 0 5 pF Z 80 20 If there are no indications for the electrolytic ...

Page 24: ...trolytic C36 VCKYPA1HF223Z J AB 0 022 µF 50V C37 RC GZA227AF1A J AB 220 µF 10V Electrolytic C38 39 VCKYPA1HF223Z J AB 0 022 µF 50V C105 106 VCKYPA1HB182K J AB 0 0018µF 50V C107 108 VCKYPA1HB821K J AA 820 pF 50V C109 110 VCKYPA1HB271K J AA 270 pF 50V C111 112 VCKYPA1HB331K J AA 330 pF 50V C113 114 RC GZA476AF1C J AB 47 µF 16V Electrolytic C115 116 VCQYKA1HM183K J AB 0 018 µF 50V Mylar C117 118 RC G...

Page 25: ...1 6W R713 VRD ST2CD102J J AA 1 kohm 1 6W R714 VRD ST2CD103J J AA 10 kohm 1 6W R715 VRD ST2CD153J J AA 15 kohms 1 6W R716 VRD ST2CD103J J AA 10 kohm 1 6W R718 723 VRD ST2CD153J J AA 15 kohms 1 6W R724 VRD ST2EE153J J AA 15 kohms 1 4W R725 VRD ST2CD153J J AA 15 kohms 1 6W R726 VRD ST2CD102J J AA 1 kohm 1 6W R727 VRD ST2EE102J J AA 1 kohm 1 4W R728 729 VRD ST2CD102J J AA 1 kohm 1 6W R730 VRD ST2EE102...

Page 26: ...RC0002SJFD J AC Spring Battery 212 JHNDP1001SJSA J AE Handle 213 QANTR0001SJZZ J AG Rod Antenna 214 MSPRZ0001SJFD J AC Spring Rod Antenna 215 GFTAB1001SJSA J AD Battery Compartment Lid 216 JKNBZ0002SJSA J AD Knob Tuning 217 JKNBK0005SJSA J AF Knob X BASS 218 JKNBZ0004SJSA J AF Knob CD 219 JKNBK0003SJSA J AC Knob Function 220 MSPRD0002SJFD J AC Spring CD Lid 221 GFTAC1001SJSA J AE Cassette Lid 222 ...

Page 27: ...QT CD121 27 A B C D E F G H 1 2 3 4 5 6 Figure 4 CD MECHANISM EXPLODED VIEW 701 304 701 302 301 702 303 M701 703x2 305x2 SW702 M702 305 PWB B 704 306 4 ...

Page 28: ...213 203 PWB A3 601x2 603x2 236 603 603 601 202 214 221 230x2 603 603 231 211 602x6 601x3 215 212 606 SW761 220 204 222 228 227 226 225 224 223 229 607x2 603x4 241 241 1 241 2 241 3 241 4 241 5 241 6 241 7 216 602 603 205 608 234 603 604x3 605x3 603x4 201 SP503 219 238 LCD701 235 218 607 607 PWB A2 603x2 603x5 603 603x4 SP504 210 206 208 209 PWB A1 SP502 232 1 232 2 207 217 243 601x2 PWB A4 PWB A5 ...

Page 29: ...TOP STATE TUNING LOW POWER FUNCTION OFF TAPE X BASS OFF SURROUND OFF VOLUME LOW Not Replacement Item 6 FRONT FRONT Polyethylene Bag Unit SSAKH0001SJZZ Packing Case SPAKC0003SJZZ Operation Manual AC Power Supply Cord Remote Control Feature Label Packing Add Left Right SPAKA0001SJZZ Bar Code Label ...

Page 30: ...QT CD121 30 M E M O 7 ...

Page 31: ...QT CD121 31 M E M O 8 ...

Page 32: ...rieval system or transmitted in any from or by any means electronic mechanical photocopying recording or otherwise without prior written permission of the publisher A9805 2002NS HA M SC LAG SHARP CORPORATION Communication Systems Group Quality Reliability Control Center Higashihiroshima Hiroshima 739 0192 Japan Printed in Japan ...

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