Jvc-UXT-770-R-Service-Manual电路原理图.pdf
SERVICE MANUALMICRO COMPONENT SYSTEMNo.20993Jun. 2001COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.UX-T770RUX-T770RContentsSafety PrecautionsImportant for laser productsPreventing static electricityDisassembly methodAdjustment methodFlow of functional operation TOC readMaintenance of laser pickupReplacement of laser pickupDescription of major ICs1-21-31-41-51-161-201-211-211-22Area SuffixE - Continental EuropeEN - Northern EuropeUX-T770R1-21. 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 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 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)UX-T770R1-3Important 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 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.REPRODUCTION AND POSITION OF LABELSWARNING LABELDANGER : 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 ärurkopplad. 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 1LASER PRODUCT!Please use enough caution not to see the beam directly or touch it in case of an adjustment or operationcheck.UX-T770R1-4Conductive material (conductive sheet) or iron plate(caption)Anti-static wrist strapPreventing 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.1.2. 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 it1.1.3. 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. 1.1.2. Ground yourself1. Use an anti-static wrist strap to release any static electricity built up in your body.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. 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. UX-T770R1-5From behind the body, remove the seven screws A retaining the rear panel.After turning the body upside down, remove the two screws B retaining the rear panel.Take out the rear panel from behind the body.1.2.3.Disassembly methodRemoving the rear panel (See Fig. 1 and 2)After turning the body upside down, remove the two screws C retaining the front cabinet assembly.After turning the body back to initial position, open the CD door while pressing the upper OPEN button.While moving the side panel (L) in the arrow direction, remove the panel from the left side of the body.While moving the side panel (R) in the arrow direction, remove the panel from the right side of the body.1.2.3.4.Removing the side panel (L) and (R) (See Fig. 2 to 5)A AAAAFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Rear panelFront panel assemblyCSide panel (L)Side panel (R)BBRear panelCD doorOPEN bottonFront panel assemblyFront panel assemblyUX-T770R1-6Remove the rear panel.Remove the left and right side panels.From the two connector CN603 and CN604 on the CD servo control board, disconnect the card wires outgoing from the connector CN304 on the power amplifier board and the connector CN766 on the LCD system CPU board.Disengage the left and right engagements a and b fixing the CD player unit by using a minus screw driver, etc.1.2.3.4.Removing the CD player unit (See Fig. 6 to 8)aCD player unitCD servo control boardCN603bCD servo control boardCN604Fig. 6Fig. 7Front panel assemblyFig. 8CD player unitFront panel assemblyPower amplifier boardCD player unitUX-T770R1-7Remove the rear panel.Remove the left and right side panels.Remove the CD player unit.Remove the five screws D and E retaining the heat sink.From the connector CN303 on the power amplifier board, disconnect the card wire outgoing from the connector CN34 on the head amplifier and mechanism control board.From the connector CN901 on the power supply board, disconnect the connector wire outgoing from the connector W306 on the power amplifier board.Remove the one screw F retaining the power amplifier board.Remove the power amplifier board from the two connectors CN711 and CN712 on the LCD system CPU board.After removing the power amplifier board from the key way c on the bottom chassis, take this board out while raising it in the arrow direction.1.2.3.4.5.6.7.8.9.Removing the power amplifier board andheat sink (See Fig. 9 to 11)Power supply boardCN901CN303CN712CN711Heat sinkLCD system CPU boardFig. 9Fig. 10Fig. 11Heat sinkDDEPower amplifier boardPower amplifier boardFront panel assemblyccFBttom chassisUX-T770R1-8Remove the rear panel.Remove the left and right side panels.From the right side of the body, remove the one screw G retaining the tuner board.From the connector CN1 and CN2 on the tuner board, disconnect the card wire outgoing from the connector CN701 and CN702 on the LCD system CPU board.Remove each tuner board backward while releasing the joint d.1.2.3.4.5.Removing the tuner board (See Fig. 12 and 13)Remove the rear panel.Remove the left and right side panels.Remove the CD player unit.Remove the power amplifier board and heat sink.From the connector CN701 on the LCD system CPU board, disconnect the card wire outgoing from the connector CN1 on the tuner board.From the bottom of the body, disengage the engagement e fixing the front panel assembly in Fig. 14 while pressing in with a minus screw driver, eta.1.2.3.4.5.6.Removing the front panel assembly (See Fig. 12 and 14)LCD system CPU boardCN701Tuner boardGFig. 12Fig. 13Fig. 14Joint dCN1Joint dTuner boardeFront panel assemblyCN702CN2UX-T770R1-9Remove the rear panel.Remove the left and right side panels.Remove the CD player unit.Remove the power amplifier board and heat sink.Remove the four screws H retaining the power transformer and power supply board and the one screw I retaining the jack holder.1.2.3.4.5.Removing the power transformer and power supply board (See Fig. 15 and 16)Remove the rear panel.Remove the left and right side panels.Remove the CD player unit.Remove the power amplifier board.Remove the front panel assembly.From inside the front panel assembly, remove the four screws J and K retaining the cassette mechanism unit.From the connector CN33 on the head amplifier and mechanism control board, disconnect the card wire outgoing from the connector CN731 on the LCD system CPU board.1.2.3.4.5.6.7.Removing the cassette mechanism unit (See Fig. 17)LCD system CPU boardCN731Cassette mechanism unitHead amplifier & mechanismcontrol boardCN33Fig. 15Fig. 16Fig. 17HHPower transformerPower supply boardIJack holderPower supply boardKJUX-T770R1-10Remove the rear panel.Remove the left and right side panels.Remove the CD player unit.Remove the front panel assembly.Remove the cassette mechanism unit.From inside the front panel assembly remove the two screws L retaining the function switch board.From the connector CN782 on the LCD system CPU board, disconnect the connector wire outgoing from the connector CN802 on the operation switch board.While sliding the two engagements f fixing the LCD system CPU board, pull out this board.After disconnect the connector CN801 on the function switch board from the connector CN781 on the LCD system CPU board, remove the respective boards while pulling them upward.1.2.3.4.5.6.7.8.9.Removing the function switch board and LCD system CPU board (See Fig. 18 and 19)L LfOperating switch boardCN802LCD systemCPU boardCN782Function switch boardLCD system CPU boardCN781CN801Function switch boardFig. 18Fig. 19f
