Jvc MXG 500 Service Manual

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MX-G500 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 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 each exposed 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 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. (This regulation does not correspond to J and C version.)

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MX-G500 1-3 ^ Importance administering point on the safety Fuse board (Forward side)Power supply board (Forward side) 4A 125V 4A 125V 4A 125V 4A 125V 4A 125V RFS5 RFS6 RFS7 RFS8RFS2 Caution: For continued protection against risk of fire, replace only with same type 4A/125V for RFS2, RFS5, RFS6, RFS7 and RFS8. This symbol specifies type of fast operating fuse. Precaution: Pour eviter risques de feux, remplacez le fusible de surete de et RFS2, RFS5, RFS6, RFS7 et RFS8 comme le meme type que 4A/125V. Ce sont des fusibles suretes qui functionnes rapide.

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MX-G500 1-9 Disconnect the card wire from the connector UCW3, UCW4, UCW5 and UCW6 on the FL display & system control board. Remove the six screws B attaching the FL display & system control board. Disconnect the card wire from the connector UCW2 on the FL display & system control board. 1. 2. 3. Removing the FL display & system control board (See Fig.1) Disconnect the card wire from the connector UCW1 on the power / CD switch board. Remove the five screws A attaching the power / CD switch board. 1. 2.Prior to performing the following procedure, remove the metal cover, the CD changer unit and the front panel assembly. Removing the power / CD switch board (See Fig.1) Prior to performing the following procedure, remove the FL display & system control board. Pull out the sound mode knob, volume knob and subwoofer level knob from front side. Remove the twelve screws C attaching the front key switch board. Remove the front board releasing the two tabs. 1. 2. 3. Removing the front key switch board (See Fig.2 and 3) Prior to performing the following procedure remove the FL display & system control board. You can pull out the headphone jack board. 1. Removing the headphone jack board (See Fig.3) Disconnect the card wire from the connector on the mecha. board. Remove the six screws D attaching the cassette mechanism assembly. 1. 2. Removing the cassette mechanism assembly (See Fig.3) Fig.1 Fig.2 Fig.3 Headphone jack board Mecha. board Cassette mechanism assembly A B B C C D D Power / CD switch board Front panel assembly (inner side ) Front panel assembly (inner side ) FL diplay & system control board Front key switch boardSound mode knob Volume knob Subwoofer level knobUCW1 UCW3 UCW4 UCW7 Tab Tab ConnectorUCW5 UCW6 UCW2 D(fixing the earth wire)

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MX-G500 1-32 LC72131(IC02) : PLL frequency synthesizer for electron alignment 12 10 9 8 7 6 2. Block diagram 54 15 193 13 CCB I/F 1 20 16 17 18 11 1 2 Reference Driver Swallow Counter 1/16,1/17 4bits 12bits Programmable Divider Power on ResetData Shift Register & Latch Unlock Detector Phase Detector Charge Pump Universal Counter 1. Pin layout 1 2 3 4 5 6 7 8 9 1020 19 18 17 16 15 14 13 12 11XOUT VSS AOUT AIN PD VDD FMIN AMIN I02 IFIN XIN CE DI CL DO BO1 BO2 BO3 BO4 I01 14 2 3.Pin function Pin No. 1 13Local oscillator signal input Symbol Functions Type Circuit configuration AMINXtal OSC FMIN 14 Serial data input : FMIN is selected when DVS is set to 1. The input frequency range is from 10 to 160MHz. The signal is passed through a built-in divide-by-two prescaler and then supplied to the swallow counter. A1 though the range of divisor setting is from 272 to 65, 535, the actual divisor is twice the setting since there is also a built-in divide-by-two prescaler. XIN XOUT 20Crystal resonator connection (4.5MHz/7.2MHz) Serial data input : AMIN is selected when DVS is set to 0. Serial data input : When SNS is set to 1 : The input frequency range is form 2 to 40MHz The signal is supplied directly to the swallow counter. The range of divisor setting is from 272 to 65, 535 and the actual divisor will be the value set. Serial data input : When SNS is set to 0 : The input frequency ranges is from 0.5 to 10MHz. The signal is supplied directly to a 12-bit programmable divider. The range of divisor setting is from 4 to 4,095 and the actual divisor will be the value set. Local oscillator signal input 2 CEChip enable Most be set high when serial data is input to the LC72131M (DI ), or when serial data is output (DO). S (1/2)