Jvc-UXF-72-MD-Service-Manual电路原理图.pdf

1-1UX-F70MD/UX-F72MDSERVICE MANUALMICRO COMPONENT MD SYSTEMNo.21028Sep. 2001COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.UX-F70MDUX-F72MDUX-F70MD/UX-F72MDContentsSafety precautionsPreventing static electricityImportant for laser productsDisassembly methodAdjustment Method 1(CD/MD section)Adjustment Method 2(Cassette mechanism section)Flow of functional operation until TOC read (CD)Flow of functional operation until TOC read (MD)Maintenance of laser pickupReplacement of laser pickup Maintenance of MD pickupProcedures of changing the MD pickupDescription of major ICs1-21-31-51-61-351-381-401-411-421-421-431-431-4471This service manual is printed on 100% recycled paper.Area SuffixUBUFHong KongChinaCOLORMD GROUP MD TITLEIMPUT/EDITCLOCK/TIMER FM MODEDISPLAY/CHARAMD TITLESEARCHSOUNDMODE AHBPROSETCANCELCDDIMMER1 2 3ENTERFM/AM/AUXREV.MODEREPEATTAPESTANDBY/ONSLEEP PLAY MODEBEEPVOLUMEMD4 5 67 8 910 0 +10RM-SUXF70MDUMARKSTANDBY/ONCOMPACTDIGITAL AUDIOMICRO COMPONENT MD SYSTEM UX-F70MDPHONESCOLORMD GROUP MD TITLEIMPUT/EDITCLOCK/TIMER FM MODEDISPLAY/CHARAMD TITLESEARCHSOUNDMODE AHBPROSETCANCELCDDIMMER1 2 3ENTERFM/AM/AUXREV.MODEREPEATTAPESTANDBY/ONSLEEP PLAY MODEBEEPVOLUMEMD4 5 67 8 910 0 +10RM-SUXF70MDUMARKSTANDBY/ONCOMPACTDIGITAL AUDIOMICRO COMPONENT MD SYSTEM UX-F72MDPHONESCA-UXF72MDCA-UXF70MDSP-UXF70MD SP-UXF70MD SP-UXF72MD SP-UXF72MD1-2UX-F70MD/UX-F72MDSafety Precautions1. This design of this product contains special hardware and many circuits and components specially for safety purposes. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Services should be performed by qualified personnel only.2. Alterations of the design or circuitry of the product should not be made. Any design alterations of the product should not be made. Any design alterations or additions will void the manufacturers warranty and will further relieve the manufacture of responsibility for personal injury or property damage resulting therefrom.3. Many electrical and mechanical parts in the products have special safety-related characteristics. These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in the Parts List of Service Manual. Electrical components having such features are identified by shading on the schematics and by ( ) on the Parts List in the Service Manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement parts shown in the Parts List of Service Manual may create shock, fire, or other hazards.4. The leads in the products are routed and dressed with ties, clamps, tubings, barriers and the like to be separated from live parts, high temperature parts, moving parts and/or sharp edges for the prevention of electric shock and fire hazard. When service is required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after re-assembling.5. Leakage currnet check (Electrical shock hazard testing)After re-assembling the product, always perform an isolation check on the exposed metal parts of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.Do not use 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 current from each exposed metal parts of the cabinet , particularly any exposed metal part having a return path to the chassis, to a known good earth ground. Any leakage current must not exceed 0.5mA AC (r.m.s.)Alternate check methodPlug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000 ohms per volt or more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by a 0.15 F AC-type capacitor between an exposed metal part and a known good earth ground.Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to eachexposed metal part, particularly any exposed metal part having a return path to the chassis, and meausre the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. voltage measured Any must not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.). Warning1. This equipment has been designed and manufactured to meet international safety standards.2. It is the legal responsibility of the repairer to ensure that these safety standards are maintained.3. Repairs must be made in accordance with the relevant safety standards.4. It is essential that safety critical components are replaced by approved parts.5. If mains voltage selector is provided, check setting for local voltage.Good earth groundPlace this probe on each exposedmetal part.AC VOLTMETER(Having 1000 ohms/volts,or more sensitivity)1500 10W0.15 F AC TYPE!CAUTIONBurrs formed during molding may be left over on some parts of the chassis. Therefore, pay attention to such burrs in the case of preforming repair of this system.1-3UX-F70MD/UX-F72MDPreventing static electricityElectrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.1.1. Grounding to prevent damage 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. 1.1.1. Ground the workbench1. Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing the traverse unit (optical pickup) on it.1.1.2. Ground yourself1. Use an anti-static wrist strap to release any static electricity built up in your body. 1.1.3. Handling the optical pickup1. In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical pickup 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 easily destroy the laser diode. 1.2. 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. Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific details, refer to the replacement 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 cable 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 itConductive material (conductive sheet) or iron plate(caption)Anti-static wrist strap1-4UX-F70MD/UX-F72MD1.3. Cautions on removing the CD traverse unit* For removing the CD traverse unit in detail, refer to the “Adjustment Method“ section of this manual.1. Before disconnecting the flexible wire from the connector CN601 on the CD SERVO board, solder the part shown in the figure below.(Note:If the flexible wire is disconnected from the CN601 without presoldering, it may cause breakdown of the CD pickup assembly.)2. When reassembling the CD traverse unit, be sure to remove the solder from the soldered part after reconnecting the flexible wire to the CN601. CD SERVO boardCD SERVO boardSoldering partCN601CN601CN321CN451PickupSoldering part bMAIN boardCD SERVO board1-5UX-F70MD/UX-F72MD1-6UX-F70MD/UX-F72MDRemove the seven screws A on the back of the body.Remove the two screws B on the bottom of the body.Unlock the speaker terminal and the antenna terminal, then remove the rear cover backward with releasing the hooks.1.2.3.Disassembly methodRemoving the rear cover (See Fig.1 and 2)Prior to performing the following procedure, remove the rear cover.Remove the two screws C attaching the side panels on the bottom of the body.Remove each side panel backward while releasing the eight joints a as shown in Fig.4 and 5.1.2.Removing the side panels (See Fig.3 to 5)Fig.1Fig.2Fig.3Fig.4Fig.5AAAAAntenna terminalRear coverSide panel (R)Side panel (L)Side panel (L)Rear coverBBSide panel (R)Side panel (R)Side panel (L)CCJoint aJoint aJoint aJoint aSpeaker terminal(Bottom)1-7UX-F70MD/UX-F72MDPrior to performing the following procedure, remove the rear cover and the side panels.Remove the two screw D on each side of the body.Release the joint b on each side of the body and remove the cassette mechanism assembly section in the direction of the arrow.Disconnect the card wires from connector CN705, CN743 and CN744 on the system control board on the left side of the body.1.2.3.Removing the cassette mechanism assembly section (See Fig.6 and 7) Prior to performing the following procedure, remove the rear cover, the side panels, the cassette mechanism assembly section and the fan assembly.Disconnect the card wire from connector CN721 on the system control board.Disconnect the card wire from connector CN522 on the underside of the MD mechanism assembly section.Remove the four screws F and the MD mechanism assembly section upward.1.2.3.Removing the MD mechanism assembly section (See Fig.8)Prior to performing the following procedure, remove the rear panel and the right side panel.Disconnect the wire from connector CN907 on the main board on the right side of the body.Remove the two screws E attaching the fan assembly.1.2.Removing the fan assembly (See Fig.6)Fig.7Fig.8Fig.6Cassette mechanism assemblyCassette mechanism assemblyEEDFan assemblyMain boardCN907CN744CN743CN705DSystem control boardCN522MD mechanism assemblyFFFFSystem control board CN721Front panelJoint bJoint b1-8UX-F70MD/UX-F72MDPrior to performing the following procedure, remove the rear cover and the right side panel.Disconnect the card wire from connector CN1 on the tuner board on the right side of the body.Remove the screw H and remove the tuner board upward while disengaging the three joint c.1.2.Removing the tuner board (See Fig.10)Prior to performing the following procedure, remove the rear cover, the side panels and the cassette mechanism assembly section.Remove the screw G on the left side of the body.Disconnect the card wire from connector CN701 and CN721on the system control board. Disconnect connector CN709, CN711 and CN712 on the system control board from the body outward.Disconnect the card wire from connector CN704 on the underside of the system control board.1.2.3.4.Removing the system control board(See Fig.9)Fig.9Fig.10System control boardGCN712 CN711CN701CN721CN709CN704CN1HJoint cTuner board1-9UX-F70MD/UX-F72MDPrior to performing the following procedure, remove the rear cover, the side panels, the cassette mechanism assembly section and the system control board.Release the two joints d on the lower right and left sides of the front panel assembly, then remove the front panel assembly toward the front.1.Removing the front panel assembly (See Fig.11 and 12)Prior to performing the following rear cover, the side panels, the cassette mechanism assembly section, the system control board and the front panel assembly section.Disconnect the wire from connector CN804 on the main board.Remove the plastic rivet fixing the headphone jack board.1.2.Removing the headphone jack board(See Fig.13 and 14)Fig.11Fig.12Fig.13Fig.14Front panel assemblyFront panel assemblyJoint dJoint dHeadphone jack boardHeadphone jack boardMain boardCN804Plastic rivet1-10UX-F70MD/UX-F72MDPrior to performing the following procedure, remove the rear cover, the side panels, the cassette mechanism assembly section, the system control board, the MD mechanism assembly section and the main board / the tuner board.Disconnect the wire from connector CN809 on the AC jack board.Remove the screw K and screw L attaching the AC jack board.1.2.Removing the AC jack board(See Fig.18 and 19)Prior to performing the following procedure, remove the rear cover, the side panels, the cassette mechanism assembly section, the system control board and the MD mechanism assembly section.Remove the screw I attaching the main board.Remove the screw H attaching the grounding terminal extending from the main board.Disconnect the wire from connector CN804 on the main board.Disconnect connector CN805 on the main board from the AC jack board while pulling out it. Remove the main board in the direction of the arrow and disconnect the wire from connector CN803 on the reverse side of the main board.Remove the three screws J attaching the heat sink on the reverse side of the main board.1.2.3.4.5.Removing the main board / the heat sink(See Fig.15 to 17)Fig.15Fig.16Fig.17Fig.18Fig.19CN804CN803IHMain boardCN805Main boardMain boardCN803CN805CN804Heat sinkHeat sinkJCN809AC jack boardAC jack boardAC jack boardCN809LKPower transformer assembly