Jvc MXK 3 Service Manual
This is the 29 pages manual for Jvc MXK 3 Service Manual.
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Extracted text from Jvc MXK 3 Service Manual (Ocr-read)
Page 1
MX-K3 1-2 Safety Precautions 1. 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 manufacturer`s 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 method Plug 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.). Warning 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 exposed metal part. AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity) 1500 10W 0.15 F AC TYPE ! CAUTION 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.
Page 2
MX-K3 1-3 Important for laser products 1.CLASS 1 LASER PRODUCT 2.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 the Laser 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 laserstrålning är denna del är öppnad och spårren är urkopplad. Betrakta ej strålen. VARO : Avattaessa ja suojalukitus ohitettaessa olet alttiina näkymättömälle lasersäteilylle.Älä katso säteeseen.ADVARSEL : Usynlig laserstråling ved åbning , når sikkerhedsafbrydere er ude af funktion. Undgå udsættelse for stråling. ADVARSEL : Usynlig laserstråling ved åpning,når sikkerhetsbryteren er avslott. unngå utsettelse for stråling. REPRODUCTION AND POSITION OF LABELS WARNING LABEL DANGER : Invisibie laser radiation when open and interlock or defeated. AVOID DIRECT EXPOSURE TO BEAM (e) VARNING : Osynlig laserstrålning är denna del är öppnad och spårren är urkopplad. Betrakta ej strålen. (s) VARO : Avattaessa ja suojalukitus ohitettaessa olet alttiina näkymättömälle lasersäteilylle.Älä katso säteeseen. (d) ADVARSEL :Usynlig laserstråling ved åbning , når sikkerhedsafbrydere er ude af funktion. Undgå udsættelse for stråling. (f) ! CAUTION Please use enough caution not to see the beam directly or touch it in case of an adjustment or operation check.
Page 11
MX-K3 1-12 Fig.18 Prior to performing the following procedures, remove the top cover. Also remove the CD changer unit. Also remove the CD changer mechanism 1. 2.Widen the section "f ". While keeping the section "f" wide open, push the section "g" in the direction of the arrow to remove the shaft, and then remove the CD pickup. Removing the CD pickup (See Fig.18) Fig.19 Fig.20 Fig.21 Prior to performing the following procedure, remove the top cover. 1. 2. 3.Pull out the CD tray. Remove the belt from the pulley. Remove the two screws "L" retaining the CD changer tray loading motor. Replacing the loading motor and belt of the CD changer tray (See Fig.19) Prior to performing the following procedures, remove the top cover. Also remove the CD changer unit. 1. 2. 3. 4. 5. 6.Remove the two screws "M" retaining the stopper brackets on both sides of the CD changer unit. Remove the stopper brackets from both sides of the CD changer unit. Pull out the CD tray from the CD changer unit, all the way and then lift the tray upward to remove. Turn the CD tray upside down and remove the tray rotor belt from the pulley. Turn the CD tray upside down and disconnect the card wire from the connector CN605 on the CD tray rotor motor assembly. Remove the two screws N retaining the CD tray rotor motor, and then remove the CD tray rotor motor. Replacing the CD tray rotor belt of the CD changer, and removing the motor (See Fig.20 and 21) L Pulley Belt CD tray M Stopper bracket N Pulley CN605CD tray rotor belt g f CD pickup Shaft
Page 19
MX-K3 1-20 Flow of functional operation until TOC read Slider turns REST SW ON. Automatic tuning of TE offset Laser ON Detection of disc Automatic measurement of Focus S-curve amplitudeAutomatic tuning of Focus offset Disc is rotated Focus servo ON (Tracking servo ON) Automatic tuning of Tracking error balance Automatic measurement of Tracking error amplitude Automatic tuning of Focus error balance Disc to be braked to stop Tracking servo on states Tracking servo off states Disc states to rotateTOC reading finishes Automatic measurement of TE amplitude and automatic tuning of TE balance500mv/div 2ms/div Fig.1 Approx.3sec pin 20 of IC611(TE) Approx 1.8V VREF Tracking error waveform at TOC reading Power ONPlay Key Confirm that the Focus error S-cuve signal at the pin32 of IC601 is approx.2Vp-p Confirm that the signal from pin24 IC601 is 0V as a accelerated pulse during approx.400ms. Confirm the waveform of the Tracking error signal. at the pin 20 of IC611 (R643) (See fig-1) Automatic tuning of Focus error gain Automatic tuning of Tracking error gain TOC reading Play a disc Confirm the eys-pattern at the lead of TP3 Confirm that the voltage at the pin5 of CN602 is "H"\"L"\"H".Check Point Check that the voltage at the pin40 of IC601 is + 5V?