JVC-MXK7-cs-sm 维修电路原理图.pdf
SERVICE MANUALCOMPACT COMPONENT SYSTEMNo.20958May. 2001COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.MX-K7MX-K7ContentsSafety precautionsImportant for laser productsPreventing static electricityDisassembly methodAdjustment methodFlow of functionaloperation until TOC readMaintenance of laser pickupReplacement of laser pickupDescription of major ICs1-21-31-41-51-181-201-211-211-22Area SuffixJU.S.A.RecordableReWritableACTIVEBASS EX.COMPACT COMPONENT SYSTEM MX-K7STANDBY/ONSTANDBYPHONESREPEATPROGRAMRANDOM/STOPREC STARTDUBBINGREC STARTCDCLOCK/TIMERTAPEA/BDISC SKIPEJECTPLAYAREC/PLAYBCD CONTROLCD 1AUXFM/AMCDTAPECD 2CD 3CD-R/RW PLAYBACKVCD NUMBERRETURNPBCMAXMINMICMICVOLCANCELSET1 BIT DUAL D/ACONVERTERPRESETTUNNIG/ DEMOCOMPU PLAY CONTROLACTIVE BASS EXTENSIONFULL - LOGIC CONTROLCD SYNCHRO RECORDINGEJECTROCKCLASSICPOPVOLUME3-CDPLAY & EXCHANGESOUNDMODERM-SMXK3A REMOTE CONTROL12345678910+10FM MODEFM /AMAUXSLEEPSTANDBY/ONCD1CD2CD3CDSOUNDMODEACTIVEBASS EX.FADEMUTINGVOLUME11PROGRAM/RANDOMREPEATTAPE A/BTAPE11111111COMPU PLAYCONTROLCA-M XK7SP-MXK7SP-MXK7SP-DSK7SP-DSK7RadioFans.CN 收音机爱 好者资料库MX-K71-21. 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.). 1. 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!Burrs 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.In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the parts that are printed over with black such as the resistor ( ), diode ( ) and ICP ( ) or identified by the mark nearby are critical for safety. When replacing them, be sure to use the parts of the same type and rating as specified by the manufacturer. (Except the J and C version)RadioFans.CN 收音机爱 好者资料库MX-K71-3Important for laser products1.CLASS 1 LASER PRODUCT2.DANGER : Invisible laser radiation when open and inter lock failed or defeated. Avoid direct exposure to beam.3.CAUTION : There are no serviceable parts inside theLaser Unit. Do not disassemble the Laser Unit. Replace the complete Laser Unit if it malfunctions.4.CAUTION : The compact disc player uses invisible laserradiation and is equipped with safety switches whichprevent emission of radiation when the drawer is open and the safety interlocks have failed or are de feated. It is dangerous to defeat the safety switches.5.CAUTION : If safety switches malfunction, the laser is able to function.6.CAUTION : Use of controls, adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.VARNING : Osynlig laserstrlning r denna del r ppnad och sprren r urkopplad. Betrakta ej strlen.VARO : Avattaessa ja suojalukitus ohitettaessa olet alttiina nkymttmlle lasersteilylle.l katso steeseen.ADVARSEL : Usynlig laserstrling ved bning , nr sikkerhedsafbrydere er ude af funktion. Undg udsttelse for strling.ADVARSEL : Usynlig laserstrling ved pning,nr sikkerhetsbryteren er avslott. unng utsettelse for strling.REPRODUCTION AND POSITION OF LABELSWARNING LABELDANGER : Invisibie laser radiation when open and interlock or defeated.AVOID DIRECT EXPOSURE TO BEAM (e)VARNING : Osynlig laserstrlning r denna del r ppnad och sprren r urkopplad. Betrakta ej strlen. (s)VARO : Avattaessa ja suojalukitus ohitettaessa olet alttiina nkymttmlle lasersteilylle.l katso steeseen. (d)ADVARSEL :Usynlig laserstrling ved bning , nr sikkerhedsafbrydere er ude af funktion. Undg udsttelse for strling. (f)!CAUTIONPlease use enough caution not to see the beam directly or touch it in case of an adjustment or operationcheck.MX-K71-4Preventing static electricity1. Grounding to prevent damage by static electricity Electrostatic 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.2. About the earth processing for the destruction prevention by static electricity In the equipment which uses optical pick-up (laser diode), optical pick-up is destroyed by the static electricity of the work environment.Be careful to use proper grounding in the area where repairs are being performed. 2-1 Ground the workbench 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.2-2 Ground yourself Use an anti-static wrist strap to release any static electricity built up in your body. 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 testers internal power source can easily destroy the laser diode. 4. Handling the CD changer unit (optical pickup)1. Do not subject the CD changer 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 CD changer 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 strapAttention when traverse unit is decomposed1. Remove the CD changer unit. 2. Disconnect the harness from connector on the CD motor board.3. Solder is put up before the card wire is removed from connector CN601 on the main board as shown in Fig.1 and Fig. 2. (When the wire is removed without putting up solder, the CD pick-up assembly might destroy.) 4. Please remove solder after connecting the card wire with CN601 when you install picking up in the substrate.*Please refer to Disassembly method in the text for pick-up and how to detach the CD changer mechanism. SolderingFig.2Flexible cableFig.1CD changermechanism assemblyCD changerunitMX-K71-5Disassembly methodTop coverCD changer unitFront panel assemblyChassis unitCD changer unitRemoving the main PCBRemoving the CD changer mechanism assemblyRemoving the CD pickupReplacing the loading motor and belt of the CD changer trayReplacing the CD tray rotor belt of CD changer, and removing the motorFront panel assemblyRemoving the cassette deck mechanismRemoving the earphone jack PCBRemoving the control/FL PCBRemoving the switch PCB and ACTIVE BASS EX. switch PCBRemoving the cassette deck main motor, and replacing the main beltsRemoving the leaf switches of the cassette deck mechanismRemoving the cassette deck headsChassis unitRemoving the 3-pin regulatorRemoving the power amp and supply PCB and the Power Trans PCBCommence disassembly of this set by removing the main units and then proceed to the components and assemblies inside the units.Replacement of the fuses and the power ICMX-K71-6Fig.1Caution Be sure to use fuses with the specified ratings.Replacing the fuses (See Fig.1)1.Prior to performing the following procedure, remove the top cover.Replace the fuses inside.1.2.Prior to performing the following procedure, remove the top cover.Also remove the rear panel and power amp and supply PCB. (See Fig.33 to 37)Remove the two screws A that retain the power IC.Remove the solder fixing the power IC. Replacing the power IC(See Fig.2 and 3)Fig.3Fig.2Replacement of the fuses and the power ICAHeat sinkFuse (F951)3.15A 125VPower trans PCBFuse (F952)1.6A 250VChassisPower amp and supply PCBPower amp and supply PCBPower ICsoldering partHeat sinkMX-K71-7Fig.4Removing the top cover (See Fig.4 and 5)1.2.3.Remove the six screws B that retain the top cover from the rear of the body.Remove the four screws C that retain the top cover from the two sides of the body.Remove the top cover from the body by lifting it toward the rear.Fig.5BBBTop coverFront panel assemblyCMX-K71-8Fig.6Caution Although the CD mechanism unit can be removed without removing the CD tray panel, it is still recommended to remove it in order to prevent damage. Prior to performing the following procedures, remove the top cover.a.b.c.1.2.3.4.5.From the front panel side of this set, push in the sections marked with arrows and pull out the CD tray toward the front.Remove the CD tray panel by pushing both of its extremities upward in the direction of the arrows.Push the CD tray deep into the set.Disconnect the cassette head wires from the connectors CN307 and CN308 on the main PCB, which is located below the CD changer unit.Disconnect the card wires from the connectors CN301, CN302 and CN305 on the main PCB.Disconnect the parallel wires from the connectors CN902A, CN902B and CN902C on the power amp and supply PCB. From the rear of the set, remove the two screws D retaining the CD changer unit, then remove the three screws E and the screw F retaining the ANTENNA terminal and the AUX IN terminal.Push down and disengage the two claws a holding the CD changer unit at the bottom of its front panel and then remove the CD changer unit (Fig. 9).Removing the CD changer unit (See Fig.6 to 9)Fig.8Fig.9Fig.7CD tray panelCD tray panelDFEAUX INterminalANTENNAterminalCD changerunitClaw aMX-K71-9Fig.10 Prior to performing the following procedures, remove the top cover.Also remove the CD changer unit.1.2.3.4.5.Disconnect the parallel wire and card wire from the connectors CN101 and CN901 on the power amp and supply PCB.Remove the two screws G retaining the front panel assembly onto the bottom of the body.Remove the screw H retaining the cassette deck mechanism and then remove the GND lug b that comes from the power amp and supply PCB.Remove the solder connecting the wire on the control/FL PCB. Disengage the claws c on both sides at the bottom of the front panel assembly and then remove the assembly.Removing the front panel assembly (See Fig.10 and 11)Fig.11GHPower amp and supply PCBControl/FL PCBClaw cGND lug bMX-K71-10Fig.12 Prior to performing the following procedures, remove the top cover.Also remove the CD changer unit.1.2.3.4.5.6.Disconnect the wires from CN602 and CN603 on the main PCB, which is located on the backside of the CD changer unit.Disconnect the card wire from connector CN604 of the main PCB at the back of the CD changer unit.The three screws I and the screw with the washer J that retain the main PCB should be removed.Remove the main PCB by pulling it toward the side where the CN601 is located.Using solder, short the CD pickup to connect to short round.Disconnect the card wire from the connector CN601 on the main PCB and then remove the main PCB.Removing the main PCB (See Fig.12 and 13)Fig.13Caution After re-connecting the wires, be sure to remove the shorting solder from the GND connection.Main PCBCN601CN603CN602CN604IIJMain PCBShort round CN601MX-K71-11Fig.14 Prior to performing the following procedures, remove the top cover.Also remove the CD changer unit.1.2.3
