Jvc-THA-25-Service-Manual电路原理图.pdf

SERVICE MANUALCOPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITEDNo.MB1432003/12DVD DIGITAL CINEMA SYSTEMMB143200312TH-A25TABLE OF CONTENTS1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-32 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-53 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-64 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-125 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13Area suffixUS - SingaporeUB - Hong KongUW - Brazil,Mexico,PeruUX - Saudi ArabiaUG - Turkey,South Africa,EgyptSOUNDVOLUMESOURCESTANDBYSTANDBY/ONDVD DIGITAL CINEMA SYSTEM TH-A251-2 (No.MB143)SPECIFICATIONDesigns & specifications are subject to change without notice.Center unit (XV-THA25)Amplifier Front/Center/Rear 30 W per channel, min. RMS, driven into 6 at 1 kHz, with no more than 10% total harmonicdistortionSubwoofer 55 W, min. RMS, driven into 3 at 100 Hz, with no more than 10% total harmonic distortionAudio Audio input sensitivity/Impedance (at 1 kHz)Analog input AUX (“AUDIO IN“) 500 mV/47 kSignal-to-Noise Ratio 68 dBDigital input* DIGITAL IN (OPTICAL) -24 dBm to -14.5 dBm (700 nm ±50 nm)* Corresponding to Linear PCM, Dolby Digital, and DTS Digital Surround (with sampling frequency-32 kHz, 44.1 kHz, 48kHz)Video Color System NTSC/PALHorizontal Resolution 480 linesOutput Level VIDEO OUT (Composite) 1.0 V(p-p)/75 S-VIDEO (Y):1.0 V(p-p)/75 (C):0.286 V(p-p)/75 COMPONENT VIDEO OUT Y 1.0 V(p-p)/75 PB/PR 0.7 V(p-p)/75 Tuner Tuning Range FM 87.50 MHz - 108.00 MHzAM 531 kHz - 1 602 kHz (at 9 kHz intervals)530 kHz - 1 600 kHz (at 10 kHz intervals)Usable Sensitivity FM 8.0 dBf (0.9 µV/75 )AM loop antenna 650 µV/mGeneral Readable Discs DVD VIDEO, Video CD, Super Video CD, Audio CD, CD-R/RW (Audio CD, Video CD, SuperVideo CD, MP3, JPEG), DVD-R/RW (Video format)Power Requirements AC 110 V - 127 V/220 V - 240 V , Adjustable with the voltage selector, 50 Hz/60 HzPower Consumption 110 W (at operation) 2 W (in standby mode)Dimensions (W × H × D) 360 mm × 65 mm × 404 mmMass 6.3 kgSubwoofer (SP-WA25)Speaker 15 cm Bass-reflex, magnetically shieldedPower Handling Capacity 55 WImpedance 3 (min)Frequency Range 30 Hz to 200 HzDimensions (W × H × D) 210 mm × 382 mm × 338 mmMass 6 kgSatellite Speakers (SP-XTHA25)Speaker 8 cm Bass-reflex, magnetically shieldedPower Handling Capacity 30 WImpedance 6 (min)Frequency Range 80 Hz to 20 kHzDimensions (W × H × D) 105 mm × 114 mm × 116 mmMass 640 g(No.MB143)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.MB143)1.5 Preventing static electricity1.5.1 Grounding to prevent damage by static electricityElectrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laserdiode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.1.5.2 About the earth processing for the destruction prevention by static electricityStatic electricity in the work area can destroy the optical pickup (laser diode) in devices such as DVD players.Be careful to use proper grounding in the area where repairs are being performed. (1) Ground the workbenchGround the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing thetraverse unit (optical pickup) on it.(2) Ground yourselfUse an anti-static wrist strap to release any static electricity built up in your body.1.5.3 Handling the optical pickup(1) In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical pick-up are shorted. After replacement, return the shorted parts to their original condition. (Refer to the text.)(2) Do not use a tester to check the condition of the laser diode in the optical pickup. The tester's internal power source can easilydestroy the laser diode.1.5.4 Handling the traverse unit (optical pickup)(1) Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit.(2) Remove solder of the short lands on the flexible wire after replacing the optical pickup. For specific details, refer to the replace-ment procedure in the text. Remove the anti-static pin when replacing the traverse unit.Be careful not to take too long a time when attaching it to the connector.(3) Handle the flexible wire carefully as it may break when subjected to strong force.(4) It is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.1.5.5 Attention when traverse unit is decomposed*Please refer to “Disassembly method“ in the text for the DVD pickup. Apply solder to the short circuit points before the flexible wire is disconnected from the connector on the DVD pickup. (If the flexible wire is disconnected without applying solder, the DVD pickup may be destroyed by static electricity.) In the assembly, be sure to remove solder from the short circuit points after connecting the flexible wire.Conductive material (conductive sheet) or iron plate(caption)Anti-static wrist strap(No.MB143)1-5SECTION 2SPECIFIC SERVICE INSTRUCTIONSThis service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.1-6 (No.MB143)SECTION 3DISASSEMBLY3.1 Main body section3.1.1 Removing the top cover(See Figs.1 and 2) (1) From the both sides of the main body, remove the fourscrews A attaching the top cover. (See Fig.1)(2) From the back side of the main body, remove the fourscrews B attaching the top cover. (See Fig.2)(3) Take out the top cover in the upward direction while ex-tending the lower sections of the top cover in the directionof right and left.Fig.1Fig.2Top coverAATop cover Rear panelB(No.MB143)1-73.1.2 Removing the tray door(See Figs.3 to 6) Prior to performing the following procedures, remove the topcover. The following procedures are performed in the case of poweron.(1) From the front side of the main body, push the disk openbottom and eject the disc tray. (See Fig.3)(2) Release the joints a in the upward direction and take outthe tray door. (See Fig.3)NOTE:The following procedures are performed in the case of poweroff.(1) From the top side of the main body, remove the fourscrews C attaching the DVD top cover. (See Fig.4)(2) Take out the disc tray in the direction of the arrow whilelifting the section b. (See Fig.5)(3) Release the joints a in an upward direction and take outthe tray door. (See Fig.6)(4) Remove the four screws D attaching the DVD mecha-nism assembly. (See Fig.6)(5) Disconnect the wires from the connectors AJ1, AJS1 andPCN1 on the DVD mechanism assembly, and take outthe DVD mechanism assembly. (See Fig.6)(6) Push in the disc tray while lifting the section b. (SeeFig.5)Reference: When pushing in the disc tray, push it until the posi-tion of the claw c. (See Fig.5)(7) Attach the DVD top cover with the four screws C to theDVD mechanism assembly.Reference: Attaching method of the DVD mechanism assemblyrefers to the section 3.1.3.Fig.3Fig.4Fig.5Fig.6Joints a Disk open buttonTray doorCCDVDmechanismassemblyDVDtop coverSection bClaws cDVD mechanismassemblyDisk trayTray doorJoints aPCN1AJ1AJS1D DDVDmechanismassemblyD1-8 (No.MB143)3.1.3 Removing the DVD mechanism assembly(See Fig.7) Prior to performing the following procedures, remove the topcover and tray door.(1) From the top side of the main body, remove the four screwsD attaching the DVD mechanism assembly.(2) Disconnect the wires from the connectors AJ1, AJS1 andPCN1 on the DVD mechanism assembly, and take out theDVD mechanism assembly.Fig.73.1.4 Removing the front panel assembly (See Figs.8 and 9) Prior to performing the following procedures, remove the topcover and tray door.(1) From the top side of the main body, disconnect the cardwire from the connector UW4 on the function board. (SeeFig.8) (2) From the bottom side of the main body, remove the fourscrews E attaching the front panel assembly. (See Fig.9)(3) From the both sides of the main body, remove the twoscrews F attaching the front panel assembly. (See Fig.9)(4) Release the joints d in forward direction and take out thefront panel assembly. (See Fig.9)3.1.5 Removing the tuner pack(See Figs.8 and 10) Prior to performing the following procedures, remove the topcover.(1) From the top side of the main body, disconnect the cardwire from the connector VW4 on video board. (See Fig.8)(2) Remove the screw G attaching the tuner pack. (See Fig.8)(3) From the back side of the main body, remove the screw Hattaching the tuner pack. (See Fig.10)3.1.6 Removing the fan motor (See Figs.8 and 10) Prior to performing the following procedures, remove the topcover.(1) From the top side of the main body, disconnect the fanmotor wire from the connector UW9 on the function board.(See Fig.8)(2) From the back side of the main body, remove two screws Jattaching the fan motor. (See Fig.10)Fig.8Fig.9Fig.10D DDVDmechanismassemblyDAJS1PCN1JS1Joint dFEFront panel assemblyVW4Front panel assembly UW4Fan motor UW9 Video boardTunerpackGFunctionboardFan motorRear panelJ H(No.MB143)1-93.1.7 Removing the rear panel(See Fig.11) Prior to performing the following procedures, remove the topcover and fan motor.(1) From the back side of the main body, remove the powercord from the rear panel in the direction of the arrow.(2) Remove the screw H, two screws K, five screws L threescrews M and attaching the rear panel.(3) Take out the rear panel.Fig.113.1.8 Removing the video board(See Fig.12) Prior to performing the following procedures, remove the topcover, fan motor and rear panel.(1) From the top side of the main body, disconnect the powercord from the connector ACW1 on the main board.(2) Disconnect the card wire from the connector VW4 on thevideo board.(3) Disconnect the video board from the connector UW7 andUW8 on the function board, and turn over the video board.(4) From the reverse side of the video board, disconnect thecard wire from the connector VW3 on the video board, andtake out the video board.Reference: Remove the tie band as required.Fig.123.1.9 Remov