JVC-THA25-ddcs-sm 维修电路原理图.pdf

《JVC-THA25-ddcs-sm 维修电路原理图.pdf》由会员分享，可在线阅读，更多相关《JVC-THA25-ddcs-sm 维修电路原理图.pdf（26页珍藏版）》请在收音机爱好者资料库上搜索。

1、SERVICE MANUALCOPYRIGHT 2003 VICTOR COMPANY OF JAPAN, LIMITEDNo.MB1432003/12DVD DIGITAL CINEMA SYSTEMMB143200312TH-A25TABLE OF CONTENTS1PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-32SPEC

2、IFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-53DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-64ADJUS

3、TMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-125TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

4、-13 Area suffixUS - SingaporeUB - Hong KongUW - Brazil,Mexico,PeruUX - Saudi ArabiaUG - Turkey,South Africa,EgyptSOUNDVOLUMESOURCESTANDBYSTANDBY/ONDVD DIGIT AL CINEMA SYSTEM TH-A25RadioFans.CN 收音机爱 好者资料库1-2 (No.MB143)SPECIFICATIONDesigns & specifications are subject to change without notice.Center u

5、nit (XV-THA25)Amplifier Front/Center/Rear30 W per channel, min. RMS, driven into 6 at 1 kHz, with no more than 10% total harmonicdistortionSubwoofer55 W, min. RMS, driven into 3 at 100 Hz, with no more than 10% total harmonic distortionAudioAudio input sensitivity/Impedance (at 1 kHz)Analog inputAUX

6、 (AUDIO IN)500 mV/47 kSignal-to-Noise Ratio68 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)VideoColor SystemNTSC/PALHorizontal Resolution480 linesOutput L

7、evelVIDEO 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 Y1.0 V(p-p)/75 PB/PR0.7 V(p-p)/75 TunerTuning RangeFM87.50 MHz - 108.00 MHzAM531 kHz - 1 602 kHz (at 9 kHz intervals)530 kHz - 1 600 kHz (at 10 kHz intervals)Usable SensitivityFM8.0 dBf (0.9 V/7

8、5 )AM loop antenna650 V/mGeneral Readable DiscsDVD 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 RequirementsAC 110 V - 127 V/220 V - 240 V , Adjustable with the voltage selector, 50 Hz/60 HzPower Consumption110 W (at

9、operation) 2 W (in standby mode)Dimensions (W H D)360 mm 65 mm 404 mmMass6.3 kgSubwoofer (SP-WA25)Speaker15 cm Bass-reflex, magnetically shieldedPower Handling Capacity55 WImpedance3 (min)Frequency Range30 Hz to 200 HzDimensions (W H D)210 mm 382 mm 338 mmMass6 kgSatellite Speakers (SP-XTHA25)Speake

10、r8 cm Bass-reflex, magnetically shieldedPower Handling Capacity30 WImpedance6 (min)Frequency Range80 Hz to 20 kHzDimensions (W H D)105 mm 114 mm 116 mmMass640 gRadioFans.CN 收音机爱 好者资料库(No.MB143)1-3SECTION 1PRECAUTION1.1Safety Precautions(1) This design of this product contains special hardware andman

11、y 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 p

12、ersonnel 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

13、 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

14、 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

15、 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

16、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 re

17、assem-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 dange

18、r of electrical shock.Do notuse a line isolation transformer during this check. Plug the AC line cord directly into the AC outlet. Using aLeakage Current Tester, measure the leakage currentfrom each exposed metal parts of the cabinet, particular-ly any exposed metal part having a return path to thec

19、hassis, 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 0.1

20、5F 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 voltag

21、e 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.). 1.2Warning(1) This equipment has been designed and manufactured tomeet international safety standards.(2) It is the

22、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

23、 for localvoltage.1.3CautionBurrs 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.1.4Critical parts for safetyIn regard with component parts appearing on the silk-screenprinted side (parts sid

24、e) 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 n

25、ot 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)1.5Preventing static electricity1.5.1Grounding to prevent damage by static electricityElectrostatic discharge (ESD), w

26、hich 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.1.5.2About the earth processing for the destruction prevention by static electricityStatic electrici

27、ty 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 o

28、ver 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.1.5.3Handling the optical pickup(1) In order to maintain quality during transport and before installation, both sides of the laser d

29、iode 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 testers internal power source can easilydestroy the laser dio

30、de.1.5.4Handling 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

31、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

32、that adjusts the laser power. Do not turn it.1.5.5Attention 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 wir

33、e 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)

34、1-5SECTION 2SPECIFIC SERVICE INSTRUCTIONSThis service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.1-6 (No.MB143)SECTION 3DISASSEMBLY3.1Main body section3.1.1Removing 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.

35、(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 coverRear panelB(No.MB143

36、)1-73.1.2Removing 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 joi

37、nts 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 whi

38、lelifting 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 t

39、ake 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: A

40、ttaching method of the DVD mechanism assemblyrefers to the section 3.1.3.Fig.3Fig.4Fig.5Fig.6Joints aDisk open buttonTray doorCCDVDmechanismassemblyDVDtop coverSection bClaws cDVD mechanismassemblyDisk trayTray doorJoints aPCN1AJ1AJS1DDDVDmechanismassemblyD1-8 (No.MB143)3.1.3Removing the DVD mechani

41、sm 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, an

42、d take out theDVD mechanism assembly.Fig.73.1.4Removing 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)

43、 (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

44、 assembly. (See Fig.9)3.1.5Removing 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. (

45、See Fig.8)(3) From the back side of the main body, remove the screw Hattaching the tuner pack. (See Fig.10)3.1.6Removing 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 c

46、onnector 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.10DDDVDmechanismassemblyDAJS1PCN1JS1Joint dFEFront panel assemblyVW4Front panel assemblyUW4Fan motorUW9Video boardTunerpackGFunctionboardFan mo

47、torRear panelJH(No.MB143)1-93.1.7Removing 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, f

48、ive screws L threescrews M and attaching the rear panel.(3) Take out the rear panel.Fig.113.1.8Removing 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 co

49、nnector 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 connec

50、tor VW3 on the video board, andtake out the video board.Reference: Remove the tie band as required.Fig.123.1.9Removing the function board(See Fig.13) Prior to performing the following procedures, remove the topcover, fan motor, rear panel and video board.(1) From the top side of the main body, disco