Sharp MD-MT821W(GL) Service Manual

MD-MT821/W– 1 –CONTENTSPageSAFETY PRECAUTION FOR SERVICE MANUAL (MD-MT821W ONLY)...

MD-MT821/W– 10 –1 Bottom Lid 1. Screw ... (A1) x5 10-12 Top Cabinet 1. Open the disc lid 10-12. Screw ...

MD-MT821/W– 11 –REMOVING AND REINSTALLING THE MAIN PARTSRemove the mechanism according to the disassembling meth-ods 1 to 6. (See Page 10.)How to remo

MD-MT821/W– 12 – Entering the TEST mode1. Setting at port (in standby state, disc-free state or power nonconnected state)(1) Set the port as follow

MD-MT821/W– 13 – Operation in each TEST mode1. AUTO1 Mode• When the STOP button is pressed while the AUTO1 menu appears or during automatic adjustm

MD-MT821/W– 14 –• When the SKIP UP button is pressed in the continuous playback mode, the specified number of lines is jumped in the FWD direction.• W

MD-MT821/W– 15 –EEPROM (IC402) writing procedure1. Procedure to replace EEPROM and write initial value of microcomputer in EEPROM(1) Replace EEPROM.(

MD-MT821/W– 16 – EEPROM DATA LIST (EEPROM version d)TEMP settingItem display Set valuesT M _ _ Calculate valuesADJ. SET settingItem display Set

MD-MT821/W– 17 –: Test Mode STOP: Pre-auto adjustment menu: ATT auto adjustment menu: Continuous record menu: EEPROM setting menu: INNER switch positi

MD-MT821/W– 18 –: ATT Autoadjustment menu: ATT adjustment error (adjustment value output): During ATT autoadjustmentAdjustment errorNormal end: ATT ad

MD-MT821/W– 19 –: RF side focus gain minor adjustment: Gain setting: A-ATT (focus) initial setting: ATT setting: B-ATT (focus) initial setting: ATT se

MD-MT821/W– 2 –Precaution to be taken when replacing and servicing the laser pickup.The following precautions must be observed during servicing to pro

MD-MT821/W– 20 –: Pre-Adjustment Value Check menu: S gain "High" A signal offset measurement value (setting): S gain "High" B sign

MD-MT821/W– 21 –: Continuous playback menu: Continuous playback (pit section): Continuous playback (groove section)# # # # : Address: Continuous playb

MD-MT821/W– 22 –: INNER switch position measurement menu: Continuous playback (pit section)# # # # : AddressPLAY I N N E RInner Switch Position Measur

MD-MT821/W– 23 –: EEPROM setting menu: Focus setting menu: Spin setting menu: Tracking setting menu: Sled setting menu: BASS setting menu: TEMP settin

MD-MT821/W– 24 –: Tracking setting menuPLAYT r a c kTracking SettingT G T F 1SKIP UP SKIP DOWN T F 2SKIP UP SKIP DOWN T F SSKIP UP SKIP DOWNT B

MD-MT821/W– 25 –: Slide setting menuPLAYS l e dSled Setting S L G S L 2SKIP UP SKIP DOWN S L MSKIP UP SKIP DOWN S L VSKIP UP SKIP DOWN S K kSKIP UP

MD-MT821/W– 26 –: Digital EQ setting menuPLAY D E Q S E TDigital EQ SettingH Q 1H Q 2SKIP UP SKIP DOWNH S GSKIP UP SKIP DOWNH S OSKIP UP SKIP DOWNL Q

MD-MT821/W– 27 –Continued from the preceding pageD R HSKIP UP SKIP DOWNP L ESKIP UP SKIP DOWNSKIP UP SKIP DOWNSKIP UP SKIP DOWNR C EE L TS L TSKIP UP

MD-MT821/W– 28 –SW401 EJECT OFF—ONSW402 HOLD OFF—ONSW403 DISC IN OFF—ONSW902 DISC PROTECT OFF—ONNOTES ON SCHEMATIC DIAGRAM• Resistor:To differentiate

MD-MT821/W– 29 – Figure 29 BLOCK DIAGRAM IC651MOTOR DRIVERLB1930M VCCIC351HEAD DRIVER74ACT02TVCC @ VEEBATTERY CASE(BOOSTER CIRCUITBUILT-IN)RECH

MD-MT821/W– 3 –FOR A COMPLETE DESCRIPTION OF THE OPERATION OF THIS UNIT, PLEASE REFER TOTHE OPERATION MANUAL. GeneralPower source: DC 3.6 V : Recha

MD-MT821/W– 30 –ABCDEFGH123456Figure 30 SCHEMATIC DIAGRAM (1/4)P30P31 P32• NOTES ON SCHEMATIC DIAGRAM can be found on page 28.OPTICAL PICKUP UNIT16R42

MD-MT821/W– 31 –78 9 10 11 12• The numbers 1 to 18 are waveform numbers shown in page 37.Figure 31 SCHEMATIC DIAGRAM (2/4)P30P31 P3216R422100KL2

MD-MT821/W– 32 –ABCDEFGH123456• NOTES ON SCHEMATIC DIAGRAM can be found on page 28.Figure 32 SCHEMATIC DIAGRAM (3/4)P30P32P31• The numbers 1 to 1

MD-MT821/W– 33 –78 9 10 11 12Figure 33 SCHEMATIC DIAGRAM (4/4)PIN NO. VOLTAGE 1 245678910111213141516171819202122232425262728293031323334353637383940

MD-MT821/W– 34 –ABCDEFGH123456Figure 34 WIRING OF P.W.BOARD (1/3)• The numbers 1 to 18 are waveform numbers shown in page 37. : Through-h

MD-MT821/W– 35 –78 9 10 11 12Figure 35 WIRING OF P.W.BOARD (2/3)CN601 CN451 L100L171C171D493C172R894Q891R893C891R891R892L710SW401EJECT15610D492L456R49

MD-MT821/W– 36 –Figure 36 WIRING OF P.W.BOARD (3/3)ABCDEFGH123456Optical Pickup Unit (15)Magnetic Head Flexible PWB (23)Magnetic Head (30)Mechanism Fl

MD-MT821/W– 37 –WAVEFORMS OF MD CIRCUITNORM:200kS / s1994 / 12 / 15 22:54:19=Filter= =Offset= =Record Length=Smoothiing : OFFBW : FULLCH1 :

MD-MT821/W– 38 –TROUBLE SHOOTINGIt is advisable to use the TEST mode (refer to Error Data Display Mode, P13) indicating the causes of troubles befores

MD-MT821/W– 39 –YesCheck whether there is defective solder joint of audio signalline between IC703 and J703NoYesIs audio wavefrom output from J703 pin

MD-MT821/W– 4 –NAMES OF PARTS Remote control unit1. Synchro Recording Indicator2. Character/Time Information Indicator3. Record Indicator4. Repeat

MD-MT821/W– 40 –• The spindle motor fails to run.Does the head moveNoDoes the waveform appear on the IC201 pins 24 and 25 afterTEST mode AUTO2 comple

MD-MT821/W– 41 –1 P12/TCLKA CIN Input Track cross signal/focus drive detection2 TCLKB SPIN Input Spindle motor FG pulse detection input3* P14 P14 Outp

MD-MT821/W– 42 –58 MD1 MD1 Input Operation mode selection input 159 P23 INNSW Input Mechanism inner SW position detection input60 WDTOVF WDTOVF Output

MD-MT821/W– 43 –PARTS GUIDENOTE:Parts marked with “ ” are important for maintaining the safety of the set.Be sure to replace parts with specified ones

PRICERANKDESCRIPTIONNO.PARTS CODE NO. PARTS CODEPRICERANKDESCRIPTIONMD-MT821/W– 1 –L751,752 VPBNN100M0000 J AC 10 µHL771 RCILC0359AFZZ J AC 100 µH,Cho

NO.PRICERANKDESCRIPTIONPARTS CODENO. PARTS CODEPRICERANKDESCRIPTIONMD-MT821/WC765,766 RC-KZ1205AFZZ J AB 0.33 µF,10VC771 VCSATE0JJ476M J AD 47 µF,6.3V

PRICERANKDESCRIPTIONNO.PARTS CODE NO. PARTS CODEPRICERANKDESCRIPTIONMD-MT821/W211 PSHEZ1022AFZZ J AB Sheet,Extension BatteryTerminal212 QTANB9401AFFQ

NO.PRICERANKDESCRIPTIONPARTS CODENO. PARTS CODEPRICERANKDESCRIPTIONMD-MT821/WTINSZ1393AFZZ J AH Operation Manual [MT821]TINSZ1394AFZZ J AE Quick Guide

MD-MT821/WABCDEFGH123456Figure 5 MD MECHANISM EXPLODED VIEW– 5 –M903M902M901503x2502x3509x2501x21150530235105138-2(SW902)8-188-3(PH901)50850350892517

MD-MT821/WABCDEFGH123456Figure 6 CABINET EXPLODED VIEW– 6 –225201223229226227228232219218233601604603x2603x2215210x2202206205217208204204-4204-2204-12

MD-MT821/W– 5 –OPERATION MANUALPOWER SOURCE Rechargeable battery powerThis unit can be used with 4 different power sources: a rechargeable battery, a

MD-MT821/W– 7 –PACKING OF THE SET (MD-MT821 ONLY)SETTING POSITION OF SWITCHES AND KNOBSUNIT HOLD OFFRemote Control HOLD CANSELBattery CaseConnecting C

MD-MT821/W— M E M O —– 8 –

MD-MT821/WCOPYRIGHT 1999 BY SHARP COPORATIONALL RIGHTS RESERVED.No part of this publication may be reproduced,stored in a retrieval system, or

MD-MT821/W– 6 –Many potential “problems” can be resolved by the owner without calling a service techni-cian.If something seems to be wrong with this p

MD-MT821/W– 7 –● The battery run down.● Nothing is recorded.● No copy can be made because of theSCMS copyright system.● A track cannot be edited.● Rec

MD-MT821/W– 8 –QUICK GUIDE (MD-MT821 ONLY)1Check the supplied accessories / Compruebe los accesorios suministrados1RELEASE LOCK31222Power source / Ali

MD-MT821/W– 9 –213RECLEVELRECENTERSYNC213RECLEVELRECENTERSYNC2134 Recording / GrabaciónAfter recording:Después de la grabación:To remove the MiniDisc: