Jvc-TDW-271-Service-Manual电路原理图.pdf

SERVICE MANUALCOPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITEDNo.MB0612004/1DOUBLE CASSETTE DECKMB061200312TD-W271TABLE OF CONTENTS1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-32 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-43 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-54 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-135 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19546372819MIN MAXINPUT LEVELCOUNTER RESETCOUNTER RESETSTANDBYSTANDBY/ON ON OFFPLAYPHONESPOWER REVERSE MODEDOUBLE CASSETTE DECKREC / REC MUTE PAUSE A B SYNCHRO DUBBINGDOLBY B-C NR HX PROPLAYREC/PLAYBACKBAUTO REVERSE3MOTOR SILENT MECHANISMAUTO REVERSE3MOTOR SILENT MECHANISMPLAYBACKADOLBY NRB OFF CAUTO TAPE SELECTOR / CONTINUOUS PLAYNORM SPEED HIGH SPEEDUF - ChinaU - Other AreasArea Suffix1-2 (No.MB061)SPECIFICATIONDesign and specifications are subject to change without notice.Type Double cassette deckTrack system 4-track, 2-channelTape speed 4.8 cm/sec (1-7/8 inch/sec) (Normal)9.5 cm/sec (3-3/4 inch/sec) (High)Frequency response(-20 dB recording)Type IV tape 20-17000Hz30-16000 Hz (±3dB)Type II tape 20-16000 Hz30-15000 Hz (±3dB)Type I tape 20-16000 Hz30-15000 Hz (±3dB)S/N ratio 58 dB (S = 315 Hz, k3 = 3%, N = A-weighted, Type IV tape)The S/N is improved by about 15 dB at 500 Hz and by max.20 dB at 1kHz 10 kHz with Dolby C NR on and improved by 5 dBat 1 kHz and by 10 dB at above 5 k Hz with DOLBY B BR on.Improvement of MOL 4 dB at 10 kHz with Dolby C NR on.Wow and flutter 0.08% (WRMS), ±0.2% (DIN/IEC)Channel separation 10 dB (1 kHz)Crosstalk 60 dB (1 kHz)Harmonic distortion k3; 0.8% (Type IV tape, 315 Hz, 0 VU)Heads Deck A METAPARM head for playback × 1Deck B METAPARM head for recording/playback,2-gap ferrite head for erasure; combination head × 1Motors Electric govemed DC motor for capstan × 1DC motor for reel × 1DC motor for mechanism drive × 1 (For both decks A and B)Fast forward/rewind time Approx. 110 sec. with C-60 cassetteInput terminals LINE IN (× 1 circuit) Input sensitivity 80 mV (0 VU)Input impeadance 50 kOutput terminals LINE OUT (× 1 circuit) Output level 300 mV (0 VU)Output impeadance 5 kPHONES × 1 Output level 0.3 mW/8 (0 VU)Matching impedance 8 - 1 k Other terminals COMPU LINK-3/SYNCRO × 2Power requirement AC 220 V, 50 HzPower consumption With power on 17 WWith power standby 4.0 WDimensions 435 × 139 331 mmMass 5.0 kg(No.MB061)1-3SECTION 1PRECAUTION1.1 Safety Precautions(1) This design of this product contains special hardware andmany circuits and components specially for safety purpos-es. For continued protection, no changes should be madeto the original design unless authorized in writing by themanufacturer. Replacement parts must be identical tothose used in the original circuits. Services should be per-formed by qualified personnel only.(2) Alterations of the design or circuitry of the product shouldnot be made. Any design alterations of the product shouldnot be made. Any design alterations or additions will voidthe manufacturers warranty and will further relieve themanufacture of responsibility for personal injury or propertydamage resulting therefrom.(3) Many electrical and mechanical parts in the products havespecial safety-related characteristics. These characteris-tics are often not evident from visual inspection nor can theprotection afforded by them necessarily be obtained by us-ing replacement components rated for higher voltage, watt-age, etc. Replacement parts which have these specialsafety characteristics are identified in the Parts List of Ser-vice Manual. Electrical components having such featuresare identified by shading on the schematics and by ( ) onthe Parts List in the Service Manual. The use of a substitutereplacement which does not have the same safety charac-teristics as the recommended replacement parts shown inthe Parts List of Service Manual may create shock, fire, orother hazards.(4) The leads in the products are routed and dressed with ties,clamps, tubings, barriers and the like to be separated fromlive parts, high temperature parts, moving parts and/orsharp edges for the prevention of electric shock and firehazard. When service is required, the original lead routingand dress should be observed, and it should be confirmedthat they have been returned to normal, after reassem-bling.(5) Leakage shock hazard testingAfter reassembling the product, always perform an isola-tion check on the exposed metal parts of the product (an-tenna terminals, knobs, metal cabinet, screw heads,headphone jack, control shafts, etc.) to be sure the productis safe to operate without danger of electrical shock.Do notuse a line isolation transformer during this check. Plug the AC line cord directly into the AC outlet. Using a“Leakage Current Tester“, measure the leakage currentfrom each exposed metal parts of the cabinet, particular-ly any exposed metal part having a return path to thechassis, to a known good earth ground. Any leakage cur-rent must not exceed 0.5mA AC (r.m.s.). Alternate check methodPlug the AC line cord directly into the AC outlet. Use anAC voltmeter having, 1,000 per volt or more sensitivityin the following manner. Connect a 1,500 10W resistorparalleled by a 0.15µF AC-type capacitor between an ex-posed metal part and a known good earth ground.Measure the AC voltage across the resistor with the ACvoltmeter. Move the resistor connection to each exposed metalpart, particularly any exposed metal part having a returnpath to the chassis, and measure the AC voltage acrossthe resistor. Now, reverse the plug in the AC outlet andrepeat each measurement. Voltage measured any mustnot exceed 0.75 V AC (r.m.s.). This corresponds to 0.5mA AC (r.m.s.). 1.2 Warning(1) This equipment has been designed and manufactured tomeet international safety standards.(2) It is the legal responsibility of the repairer to ensure thatthese safety standards are maintained.(3) Repairs must be made in accordance with the relevantsafety standards.(4) It is essential that safety critical components are replacedby approved parts.(5) If mains voltage selector is provided, check setting for localvoltage.1.3 CautionBurrs formed during molding may be left over on some partsof the chassis. Therefore, pay attention to such burrs in the case of pre-forming repair of this system.1.4 Critical parts for safetyIn regard with component parts appearing on the silk-screenprinted side (parts side) of the PWB diagrams, the parts that areprinted over with black such as the resistor ( ), diode ( )and ICP ( ) or identified by the “ “ mark nearby are criticalfor safety. When replacing them, be sure to use the parts of thesame type and rating as specified by the manufacturer. (This regulation dose not Except the J and C version)Good earth groundPlace this probe on each exposedmetal part.AC VOLTMETER(Having 1000 ohms/volts,or more sensitivity)1500 10W0.15 F AC TYPE1-4 (No.MB061)SECTION 2SPECIFIC SERVICE INSTRUCTIONSThis service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.(No.MB061)1-5SECTION 3DISASSEMBLY3.1 Enclosure section3.1.1 Removing the top cover (See Fig.1)(1) Remove four screws A retaining the top cover from bothside.(2) Remove two screws B retaining the top cover from theback side.(3) To remove the top cover, slide in direction of arrow and liftaway (refer to Fig.1).Fig.13.1.2 Removing the front panel assembly (See Fig.2, 3)(1) Remove the top cover as described in above.(2) Remove the three screws C retaining the front panel as-sembly from bottom side.(3) Release the front panel assembly from two pawls in thefront and bottom sides and draw it to the front side.(4) Disconnect all connectors between the mechanism assem-bly, front panel assembly and main board.Fig.2Fig.3AABMBTop coverCPawlC CPawlFront panel assemblyPull 2Pull 2Push 1Push up with a screwdriver, etc. 11-6 (No.MB061)3.1.3 Removing the mechanism assembly Although the mechanism assembly can be removed withoutdetaching the front panel assembly, it is recommended to de-tach the front panel assembly to do the work with ease.(1) Remove the two screws D or two screws E from the cor-ners of the mechanism. (Fig.6)(2) Open the door and remove the mechanism assembly.(At this time, door lock arm spring and door lock arm are re-moved together with.)(3) For moving the mechanism assembly only, disconnect thefollowing wirings.a) Mechanism assembly side (Fig.5)Top side connector of the cam switch board (CN2).Connector of the motor board (CN1). (Board to boardconnector)b) Main board side (Fig.4)Disconnects CN802 from mecha control board,CN801 from switch/volume board and CN861 fromheadphone jack board.Disconnect wire coming from the head mount assem-bly CN811 at deck A and CN815 at deck B.Remove one screw F and remove one GND wirefrom mechanism control board.3.1.4 Removing the eject arm assembly (Fig.6)(1) Remove the screws G retaining the eject arm assemblyand pull it out.Fig.4Fig.5Fig.6Main boardMechanism control boardCN811CN861CN801CN802CN815From DECK AFrom DECK BDECK AFrom Mechanismcontrol boardFrom Headphone jack boardFrom Switch/ Volume boardLDECK BFMotorboardMotorboardMotorboardMotorboardMechanismcontrolboardMechanismcontrolboardMechanism control boardCamswitchboardCam switch boardDECK B DECK ACam switch boardCamswitchboardDECK B DECK ADDGGEE(No.MB061)1-73.1.5 Removing the mechanism holder and door assembly (Fig.7, 8)(1) Remove four screws H retaining the mechanism holder.(2) Remove the damper assembly (for easy reassemblingwork).Insert an originary (-) screwdriver or the like in to the gapbetween the damper and the front panel to disengage thepawl, and draw the damper assembly outwards. (SeeFig.7)(3) Remove the arm shaft of the cassette holder (door assem-bly) from the mechanism holder. (The door spring is en-gaged with the door side by the longer side.) (See Fig.8)(4) Remove the eject spring from lock lever and mechanismassembly. (See Fig.8)Fig.7Fig.8PawlHow to remove damperCassette doorLonger sideShorter sideMechanism assemblydoor springeject springLock leverHow to engage the door and eject spring1-8 (No.MB061)3.1.6 Removing the switch & volume board (Fig.9)(1) After removing the mechanism holder, proceed to the fol-lowing steps.(2) Pull out the INPUT volume knob.(3) Remove four screws J, one screw N and cap retaining theswitch/volume board.(4) Lift the board right upwards to remove it since it is connect-ed to the key switch board with connector pins (CN603/CN604).(5) Disconnect CN602 coming from Mechanism control board(CN702).3.1.7 Removing the headphone jack board (Fig.9)(1) After removing the switch/volume board, pull the head-phone jack board outwards while pushing it down towardthe bottom side to remove it.3.1.8 Removing the key switch board (Fig.9)(1) Remove one screw K (Deck A or B) retaining the board.(2) Do the same for the other side.Fig.93.1.9 Removing the main board (see Fig.4 and 1)(1) Remove three screws L retaining the board.(2) Remove four screws M retaining the board to the rear pan-el.3.1.10 Reassembling procedure of the front panel assembly(1) Attach the key switch board to the panel with two screws.(2) Attach the mechanism holder to the front panel assemblywith four screws.(3) Put the door assembly on the front panel.(4) Engage the door spring properly.(5) Install the damper. (Push the pawl side last to engage it.)(6) Install the mechanism assembly.(7) Attach the mechanism control board to the panel with twoscrews.(8) Install the eject arm assembly.(9) Attach the switch/volume board to the panel with fivescrews.(10) Hook the eject spring between lock lever and mechanismassembly.Mechanism control boardKey switch boardSwitch/Volume boardHeadphone jack boardKey witch boardKey switch boardCapNJH HKHKH JCN604 CN603CN602CN702J(No.MB061)1-93.2 Cassette mechanism section3.2.1 Removing the head mount assembly (Fig.10 and 11)(1) Remove the FPC holder from the mechanism frame in thedirection indicated by the arrow (A).(2) Remove three screws A retaining the head mount assem-bly.3.2.2 Removing the pinch roller assembly (Fig.10 and 12)(1) Remove the pinch roller and pinch roller spring, refer toFig.12.Fig.10Fig.11Fig.12Mechanism APinch roller (left) Pinch roller (right)Head mount assemblyHead mount assemblyHead baseFPC Holder(A)APinch roller(left)Pinch roller(right)Pinch rollerspringPinch rollerspringPawlPawl1-10 (No.MB061)3.2.3 Removing the FM bracket/Capstan motor assembly(Mechanism A and B)(1) Remove soldering of connector FM on reel motor board.(Fig.13)(2) Remove three screws B and disengage two pawls, andthen the FM bracket and the capstan belt can be removed.(Fig.13 and 14)(3) Remove two screws C retaining the capstan motor from theFM bracket. (Fig.13)(4) For reengaging the capstan belt, refer to Fig.14.Fig.13Fig.143.2.4 Removing the flywheel assembly (Fig.15)(1) Remove two screws D and remove the shield plate.(2) Pull up the flywheel (L) and (R), and remove them.3.2.5 Removing the reel motor board (Fig.15)(1) Remove four soldering of the reel motor and actuator mo-tor, and remove the reel motor board.Fig.15PawlPawlReel motor boardConnector FMCapstan motorFM bracketBBBCCapstan beltReel motorReel motor boardSolderingSolderingActuator motorFlywheel (R) Flywheel (L)Shield plateD