Jvc MXG 78 V Service Manual
This is the 65 pages manual for Jvc MXG 78 V Service Manual.
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Extracted text from Jvc MXG 78 V Service Manual (Ocr-read)
Page 1
MX-GT98V/MX-GT95V/MX-GT88V MX-GT85V/MX-G78V/MX-G75V 1-2 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 current 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 each exposed metal part, particularly any exposed metal part having a return path to the chassis, and measure 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 exposed metal part. AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity) 1500 10W 0.15 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&C version)
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MX-GT98V/MX-GT95V/MX-GT88V MX-GT85V/MX-G78V/MX-G75V 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 laser radiation and is equipped with safety switches which prevent emission of radiation when the drawer is open and the safety interlocks have failed or are defeated. 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. Position of labels WARNING LABEL !CAUTIONPlease use enough caution not to see the beam directly or touch it in case of an adjustment or operation check. 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) CLASS 1 LASER PRODUCT CLASS 1 LASER PRODUCT
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MX-GT98V/MX-GT95V/MX-GT88V MX-GT85V/MX-G78V/MX-G75V 1-8Prior to performing the following procedure, remove the metal cover. Disconnect the card wire from connector CN1 on the tuner board on the right side of the body. Remove the plastic rivet fixing the tuner board. Remove the two screws G on the back of the body. 1. 2. 3. Removing the tuner board (See Fig.12) Prior to performing the following procedure, remove the metal cover and the CD changer mechanism assembly. Remove the screw H attaching the rear cover on the back of the body. Push each tab of the four joints b in the direction of the arrow and release. Remove the fifteen screws G attaching the rear panel. Disengage the joints c on each lower side of the rear panel using a screwdriver and remove the rear panel backward. 1. 2. 3. 4. Removing the rear cover / rear panel (See Fig.13 to 16) Fig.12 Fig.13 Fig.14 Fig.15 Fig.16 CN1 Plastic rivetTuner board Rear panel Rear panel H G Joint b Joint b Rear cover Rear panel G G GG G Joint c Joint c Rear panel Rear panel G
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H AB C DE FG 12 3 45 2-6 MX-GT98V/MX-GT95V/MX-GT88V MX-GT85V/MX-G78V/MX-G75VMX-GT98V/MX-GT95V/MX-GT88V MX-GT85V/MX-G78V/MX-G75V Front key section SHEET 5/9 SHEET 4/9 SHEET 4/9 SHEET 4/9 SHEET 2/9 TW800 FW915 CN870C901 Q956 Q960 Q953 Q918 Q954 Q941 Q940 C1070C935 FW901C1021 C902Q919 JS901 D1003 S901 S902Q920 D1062 S931 S932 S933S951 R930S935C962 C963 JS962 S936 S937 S939 J1001 TW801 S938 L1002 FW713 S952JS956 C960JS960 C961 S950 S942 S944 S943 S945 S949 S948 S947 S946 S915 S917S916R1068 R1021 R1022J1022 J1021 Q1061IC901 C1068 R1069C1066D1061 R1062R1063 D945 D942 D944 D943R955R908 L1003D904 R904 D905 Q901 R929 R954 R951 D954 R938 R941 R932 R933 R935 R940 R939 D940 R931 D941 R937 R953 R952 R936 L1001 C1002C1001C1004 C1006 C1005R916 D953D957 D956 C956 C957 R956 D961 D960 R960 R942 R944 R943 R946R947 R948R949 R945R950D919 R917 D918 D920R919 R920 C1022 C1023VR901 R1071 R1070 C1065 C1067 R1067 R1066 C1063 R1061 C1062 C1061 R1065 R1064 C1064R918 QUB220-15DMHP QUM027-18Z4Z4 0.01 2200p0.01 QUM027-13DGZ41000p 0.01 QSW0911-001 MTZJ2.4B-T2 MTZJ2.4B-T2 10K0.01 0.01 QSW0862-001 QNS0183-001 QUB220-15DMHP QQL231K-470Y QUM153-33DGZ4QSW0912-001 0.01QSW0911-001 0.01 20K 4.7k 4.7kQNS0184-001 QNS0184-001 2SD2144S/VW/-TNJM4580L 0.22/50 1K330P1SS133-T2 12K 390 KTA1267/YG/-TKTA1267/YG/-T KTA1267/YG/-TKRC102M-T KTA1267/YG/-T KTA1267/YG/-T KTA1267/YG/-T1.5KKRC102M-T 5.6K QQR0779-001Z68 L-115XSRD-D-T KRC102M-T2 KRC102M-T 2K 68 2K L-914SRD-T 2.2K 68 2.7K 3.9K 5.6K 68 2.7K L-914SRD-T 2.2K L-914SRD-T 1.5K 68 1.2K 1.2K QQL231K-470Y 3900p 3900p1000p 1000p 1000p1K L-914SRD-TSLA-362LT-T 0.01 0.01 68 SLA-362LT-T 68 3.9K 3.9k 10K2.7K 1.5k1.2k 2.2k 5.6K 1kSLA-362LT-T 1K SLA-362LT-T SLA-362LT-T200 200 1000p 1000pQVQ0299-B54 4.7K 560 150P 2.2/50 56 4.7M 4.7/50 10K 100/10 220/10100 1.5k150P200