Jvc-PC-XC350-Service-Manual电路原理图.pdf
PC-XC350SERVICE MANUALCD PORTABLE COMPONEMT SYSTEMPC-XC350contentsSafety precaution - 1-2 Block/Wiring Diagram - 1-16Disassembly method - 1-4 Circuit Diagram - 1-18Adjustment method - 1-6 PCB drawing - 1-20TOC read - 1-11 Assembly - 1-22Major IC Description -1-12 Packing - 1-32No. xxxxxCOPYRIGHT © 2001 VICTOR COMPANY OF JAPAN,LTD (By JCA)OCT 2001Area SuffixJ-USAC-CANADAUnit No.SP-PCXC350Unit No.SP-PCXC350Unit No.SP-PCXC350PC-XC3501. This design of this product contains special hardware and many circuits and components specially forsafety purposes. For continued protection, no changes should be made ti the original design unlessauthorised in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Services should be performed by qualified personel 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 warrantyand will further relieve the manufacturer of responsibility for personal injury or property damageresulting therefrom.3. Many eletrical 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 bythem necessarily be obtain by using replaement components rated for higher voltage, the PartsList of Service manual. Electrical components having such features ate identified by the shading on the schematics and by ( ) on the parts List in the Service Manual. The use of a substitute repalcement 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, tubing's, barriers and the like to be separated from live parts, high temperatures parts, moving parts and/or sharp edges for the prevention of electric shcok and fire hazard. When service is required, the original leat routing and dress should be observed, and it should be confirmed that they have been returned to normal, afterre-assembling.5. Leakage current check (Electrical Shock hazard testing)After re-assembling the product, always perform an isolation check on the exposed metap 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 isloation transformer during this check.Plug the AC line cord directly into the AC outlet. Using a “Leakage Current Tester“, measure theleakage current from each ecposed metal parts of the cabinet, particularly and exposed metalpart having a return path to the chassis, to a known good earth ground. Any leakage current mustnot 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 pervolt or more sensitvity in the following manner. Connect a 1,500 ohm 10W resistor paralleled by a0.15uF AC-type capacitor between an exposedmetal part and a known good earth ground.Measure the AC voltage across the resistor withthe AC voltmeter.Move the resistor connection to each exposedmetal part, particularly and exposed metal parthaving a return path to te chassis andmeasure the AC voltage across the resistor. Now,reverse the plug in the AC outlet and repeateach measurement. Voltage measured Any mustnot exceed 0.75 V AC (r.m.s.). This correspondsto 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. It mains voltage selector is provided, check setting for local voltage.CAUTION Burrs formed during moulding may be left over on some parts of the chassis. Therefore,pay attention to such burrs in the case of performing repair of this system.Safety PrecautionsWarning1 - 2PC-XC350Preventing 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 pcikup). Take care to prevent this when performing repairs.1.1. Grounding to prevent damage by static electricityStatic electricity in the work area can destroy the optical pickup (laser diode) in devicessuch as DVD players.Be careful to use proper grounding in the area where repairs are being performed.1.1.1. Gound the workbench1. Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate overit before placing the traverse unit (optical pickup) on it.1.1.2. Ground yourself1. Use an anti-static wrist starp to release and static electricity built up in your body.1.1.3. Handling the optical pcikup1. In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical pickup are storted. 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 laserdiode in the optical pickup. The tester's internal powersource can easily destory the laser diode.1.2. Handling the traverse unit (optical pickup)1. Do not subject the traverse unit (optical pcikup) 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 specificdetails, refer to the replacement procdeure in the text. Remove the anti-static pin when replacing the traverseunit. Be careful not to take too long a time when attaching itto 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 return it.1 - 3PC-XC350Disaeesmbly methodRemoving the rear panel1. From behind the body, remove the eight screws Aretaining the rear panel.2. Then remove the two screws B retaining the rear panel.3. Take out the rear panel from the body.Note:Be careful of the FM antenna white wire, it is connection with the tuner PCB up side.You can directly take out from the tuner PCB.When you re-assembly the product, plug the FM antenna white wire into the Tuner PCB's “FM ANT“ position.1 - 4Screw A.Screw A.Screw B.PC-XC350Removing the CD mechanismE1. Remove the rear panel2. Removing the two screws E retaing the 3CD mechanism cover.3. Removing the crew F retaing the control PCB left side.E4. Remove the srews G retaing on the 3CD mechanism cover& the two screws H retaining on the control PCBFGHRemoving the Main PCB1. Remove rear panel2. Remove the 3CD mechanism3. Remove the four screws attaching themain PCB.1 - 5PC-XC350Adjustment methodMeasurement instruments required for Tuner sectionadjustmentVoltage applied to tuner - +B:DC 5.7V1. Low frequency oscillator VT: FM 25v / am 1.57.5vThis oscillator should have a capacity to output Reference measurement - 26.1mV(0.866/30dB to 600 at an oscillation frequency of output50Hz-20KHz Input positions - AM : Standard loop antennaFM : TP1 (hot) and TP2 (GND)2. Electronic voltmeter3. Distorion meter4. Frequency counter Standard measurement position of volumett 5. Wow & flutter meter6. Test tape Bass - OffTCC-112: tape speed and running unevenness (3KHz) EQ - FlatTCC-140: Reference level (1KHz) UP and down adjustment of volume - Vol : 16TCC-182A: Head angle (8KHz), playback frequencycharacteristics (1KHz) and dubbing frequency Precautions for measurementcharateristics (125Hz and 8KHz) 1. Direct connect to the IF sweeper outputside and 1 UF and 22 Kohm connect to the 7. Black tape sweeper input side. Same as FIG. 1.TYPE I : TDK-D608. Torque gauge : For play and tensionFWD(CT-120m), and FF/REW(CT-F)Measurement conditionsPower supply voltage-AC 120V (60Hz)Reference output-Speaker : 0.866V/3 2. The IF sweeper output level should be made as Headphone : 0.245V/32 low as possible within the adjusttable range.Reference frequency and -1KHz, AUX : 450mV 3. Since the IF sweeper is a fixed device, there is noinput level need to adjust this sweeper.Input for confirming recording and-CD : -10dB 4. Since a ceramic oscillator is used, there is no needplayback characteristics to perform and MIX adjustment.Measurement output terminal-Speaker CN301 5. Since a fixed coil is used, there is no need to*Load resistance-3 adjust the FM tracking.6. The input and output earth systems are separated.In case of simuitaneously measuring the voltage in Radio Input signal both of the input and output systems with anelectronic voltmeter for two channels, therefore, theAM frequency -400Hz earth should be connected particularly carefully.AM modulation-30% 7. In the case of BTL connection amp., the minusFM frequency -1 KHz terminal of speaker is not for earthing. Therefore, beFM frequency deviation -22.5KHz sure not to connect any other earth terminal to this terminal. This system is of an BTL system.8. For connecting a dummy resistor when measuringthe output, use the wire with a greater code sze.9. Whenever any mixed tape is used, use the band pass filter (DV-12V)1 - 6PC-XC350TUNER ADJUSTMENTuse a plastic screews driver for adjustments.Adjust the intermediate frequency of AM and FM to the frequency of cermic filter.Supply voltage: DC 12.0VSpeaker impedance: 3 OHMSFunction switch: RADIOa. AM adjustment BAND SELECT SWITCH : AMste Adjusting Tuning Adjustmentcircuit Frequency Measurement input Measurement output parts1 IF 1000 KHz AM Sweep Loop VTVM TP16 (H) T103(450 KHz) Generator ANT Oscilloscope TP 8 (E)2 Tuning 530 KHz Digital TP16 (H) T1023 Coverage 1710 KHz Voltmeter TP 8 (E)4 Tracking 600 KHz Am signal Loop VTVM TP12 (L) MW COIL5 1500 KHz Generator ANT Oscilloscope TP11 (R) CT102b. FM Adjustment BAND SELECT SWITCH : FM FM Dummy Antenna : 75 ohm unbalanceste Adjusting Tuning Adjustmentcircuit Frequency Measurement input Measurement output parts1 IF FM Sweep TP4 (H) VTVM TP16 (H)(10.7 MHz) 98.0 MHz Generator TP8 (E) Oscilloscope TP8(E) T1042 Tuning 87.5 MHz Digital TP16 (H)3 Coversage 108 MHz - - Voltmeter TP8(E) L1044 Tracking 90.0 MHz FM Signal FM ANT VTVM TP12 (L) L1035 106.0 MHz Generator TP1(E) Oscilloscope TP11 (R)Input Connection Output Connection VTVM Oscilloscopenear by effective1.2+/-0.05VConfirm 7.0+/-0.5VMaximumsensitvityOutput ConnectionInput Connection VTVM OscilloscopeConfirm 1.4+/-0.1V5.6+/-0.5VConfirm with being1 - 7PC-XC350ARRANGEMENT OF ADJUSTMENTS POSITION 1 - 8PC-XC350Tape recorder sectionItems Measurement Measurement method Standard Adjustingconditions Values positionConfirmation Test tape 1 Playback the test tape TCC-182A (8KHz) Maximum Adjust the headof head angle : TCC-182A(8KHz) 2 With the recording & playback mechanism, output azimuth screwMeasurement output adjust the head azimuth screw so that the onlyterminal left and right output leavers become: Speaker terminal maximum, After adjustment, lock the headSpeaker R/L azimuth at least by half turn.(Load resistance: 3: Headphone terminalConfirmation Test tape Adjust VR401 so that the frequency counter Tape speed VR401of tape speed : TCC-112 (3KHz) reading becomes 3,010Hz +/-15Hz when of deckplaying back the test tape TCC-112 (3KHz) with :3,010Hzplayback and recording mechanism after +/-15HzMeasurement output ending forward winding of the tape.terminal: Headphone terminalReferemce Values for Confirmation ItemsItems MeasurementMeasurement methodStandard Adjustingconditions Values positionWow & flutter Test tape When the test tape TCC-112 (3KHz) has been 0.25% or:TCC-112(3KHz) played back with the recording and playback lessmechanism at the beginning of forward (WRMS)winding, the frequency counter reading of Measurement output wow & flutter should be 0.25% or lessterminal (WRMS).:Headphone terminal1 - 9PC-XC350Electrical PerformanceItems Measurement Measurement method Standard Adjustingconditions Values positionAdjustment of Mode: Playback 1 With the recording and playbackrecording blas mode mechanism, load the test tapes TDK-D60current Recording mode TDK-D60, and set the mechanism to the 4.5 u A(Reference Test tape recording and pausing condition in advance. +/-0.5u AValue) TDK-D60Measurement output 2 After connecting 100 in series to theterminal recorder head, measure the blas current: Both recording and with a valve voltmeter at both of theheadphone terminals terminalsAdjustment of Reference frequency 1 with the recording and playback Outputrecording and :1KHz and 8KHz mechanism, load the test tapes (TDK-D60) deviationpalyback (REF.:-10dB) and set the mechanism to the betweenfrequency Test tape recording and pausing condition in 1KHz and characteristics TDK-D60 advance 8KHzMeasurement input 2 While repetitively inputting the reference :-1dB +/-2dBterminal frequency signal of 1KHz and 8KHz from: OSC IN OSC IN, record andplayback the tape.3 While recording and playback the test tapeLch and Rch so that the outputdeviation between 1KHz and 8KHz from-1dB +/-2dBReference Values for Electrical Function Confirmation ItemsItems Measurement Measurement method Standard Adjustingconditions Values positionRecording Playback 1 While changing over t and form BIAS 1 64KHz T201blas Test tape and 2, confirm that the frequency is +/-6KHzfrequency TDK-D60 changed.Measurement 2 With the recording and playbackterminal : BIAS TP on mechanism, load the test tape.P.C. board (TDK-D60), and set themechanism to the recording and pausingcondition in advance.3 Confirm that the BIAS TP frequency on theP.C. board is 64KHz +/-6KHz1-10
