JVC-RCBX33SL-cs-sch 维修电路原理图.pdf

SERVICE MANUALPORTABLE CD SYSTEMContentsSafety precautions .1-2Preventing static electricity .1-3Disassembly method.1-4Adjustment method.1-7Description of major IC.1-13RC-BX33SL? ? !?#$?%?$ ?&?(?)? ?*?+?,?(?(?-?(?(?./? 0?(?& &?1 ?(?2,?33?4? ?2?&,?0?(?& &?)?&?(? ?(?(?&?(?No: 28208DEC. 2001COPYRIGHT 2001 JVC ASIA PTE LTDRC-BX33SLArea SuffixUX-Saudi and relativeU-Except uxRadioFans.CN 收音机爱 好者资料库XL-SV320SL/SV305GDXL-SV308BU1-2RC-BX33SL1. This design of this product contains special hardware and many circuits and components specially forsafety purposes. For continued protection, no changes should be made to the original design unlessauthorised in writing by the manufacturer. Replacement parts must be identical to those used in theoriginal 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 theproduct should not be made. Any design alterations or additions will void the manufacturers warrantyand will further relieve the manufacture of responsibility for personal injury or property damage resultingtherefrom.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 bythem necessarily be obtained by using replacement components rated for higher voltage, the PartsList of Service Manual. Electrical components having such features are identified by shading on theschematics and by () on the Parts List in the Service Manual. The use of a substitute replacementwhich does not have the same safety characteristics as the recommended replacement parts shownin 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 tobe separated from live parts, high temperature parts, moving parts and/or sharp edges for the preventionof electric shock and fire hazard. When service is required, the original lead routing and dress shouldbe 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 theproduct (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 theleakage current from each exposed 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 sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by aWarning1. 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.0.15F AC-type capacitor between an exposedmetal part and a known good earth ground.Measure the AC voltage across the resistorwith the AC voltmeter.Move the resistor connection to each exposedmetal part, particularly any exposed metal parthaving a return path to the chassis, andmeasure the AC voltage across the resistor.Now, reverse the plug in the AC outlet andrepeat each measurement. voltage measuredAny must not exceed 0.75 V AC (r.m.s.). Thiscorresponds to 0.5 mA AC (r.m.s.).Safety precautions0.15F AC TYPE1500 10WPlace thisprobe oneach exposedmetal part.Good earth groundAC Voltmeter(Having 1000ohms/volts,or more sensitivity! 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.RadioFans.CN 收音机爱 好者资料库RC-BX33SL1-3Preventing static electricityElectrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is dis-charged, can destroy the laser diode in the traverse unit (optical pickup). Take care to prevent this whenperforming repairs.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.1.1.1. Ground 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 strap to release any static electricity built up in your body.1.1.3. Handling the optical pickup1. In order to maintain quality during transport and before installation, both sides of the laser diode on thereplacement optical pickup are shorted. After replacement, return the shorted parts to their originalcondition. (Refer to the text.)2. Do not use a tester to check the condition of the laser diode in the optical pickup. The testers internalpower source can easily destroy the laser diode.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 spe-cific details, refer to the replacement procedure in the text. Remove the anti-static pin when replacing thetraverse 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 it.Conductive material(conductive sheet) oriron plate(caption)Anti-static wrist strapRC-BX33SLDisassembly methodRemoving the rear panel1. From behind the body, remove the Five screws Aretaining the rear panel.2. Open the Battery door, then remove One Screw B retaining in the battery compartmentbottom side.3 Then remove the Two screws C retaining the bottom of rear panel.4 Take out the rear panel from the body. And disconnect the CN302 on the main board right side.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 PCBS FM ANT position.Screw A.Screw A.Screw C.Screw C.Screw B. 1-4 RC-BX33SLRemoving the Main Board PCB (1)1. Open & remove the rear panel2. Remove the Two Screws D on the Black Backet,then take out the black backet on the front panel.Screws D.3 Remove the Two Screws E retaining on theleft of front panel.Screws E.4 Remove the One Screw F retaining on theright of front panel.Top panelScrew F.1-5RC-BX33SLRemoving the Main Board PCB (2)5 Disconnect the CN201, CN202 & C301 on the top of the Main Board PCB.Front PanelCN 201CN 202Main PCBCN 301Top Panel6 Then, take out the top panel from the front panel.7 Remove the nine screws G from the Main Board PCB.Screw G.Screw G.Screw G.8 Take out the Main Board PCB from the front panel, & disconnect the CN901 & CN903on the Main Board PCB.1-6RC-BX33SLAdjustment methodMeasurement instruments required forTuner sectionadjustment1Low frequency oscillator Reference measurement - 26.1mV(0.63/8?)This oscillator should have a capacity to outputoutput0dB to 600? at an oscillation frequency ofInput positions - AM : Standard loop antenna50Hz-20KHz FM : TP1 (hot) and TP2 (GND)2Electronic voltmeter3Distortion meterPrecautions for measurement4Frequency counter1Direct connect to the IF sweeper output5Wow & flutter meterside and 1UF and 22 Kohm connect to the 6Test tapesweeper input side. Same as FIG1.TCC-112: Tape speed and running unevenness (3KHz)1 UTCC-140: Reference level (1KHz)IC101TP16TCC-182A: Head angle (8KHz), playback frequencyPIN1822 K characteristics (1KHz) and dubbing frequencyTP8 characteristics (125Hz and 8KHz)7Blank tape2The IF sweeper output level should be made asTYPE I : TDK-D60low as possible within the adjustable range.3Since the IF sweeper is a fixed device, there is8Torque gauge : For play and back tensionno to adjust this sweeper.FWD(CT-120m), and FF/REW(CT-F)4Since a ceramic oscillator is used, there is noneed to perform any MIX adjustment.Measurement conditions5Since a fixed coil is used, there is no need toadjustment the FM tracking.Power supply voltage - AC120V (60Hz)6The input and output earth systems are separated.Reference output - Speaker : 0.63V/8?In case of simultaneously measuring the voltage Headphone : 0.245V/32?in both of the input and output systmes with andelectronic voltmeter for two channels, therefore,the earth should be connected particularlyInput for confirming recording and - CD : -10dBcarefully.playback characteristics7For connecting a dummy resistor when measuringMeasurement output terminal - Speaker CN301the output, use the wire with a greater code size.* Load resistance - 8?8Whenever any mixed tape is used, use the band pass filter (DV-12V).Radio Input signalAM frequency - 400HzAM modulation - 30%FM frequency - 1 KHzFM frequency deviation - 22.5KHz1-7RC-BX33SLTAPE DECK ADJUSTMENTS1HEAD AZIMUTH ADJUSTMET ( 1 ) Load the test tape TCC-182A 8KHz for azimuthadjustment.( 2 ) Press the PLAY button.Use a cross-tip screwdriver to turn the screw for azimuth( 3 ) adjustment so that the left and right output are maximized( 4 ) Press the STOP button( 5 ) After completion of the adjustment. Use thread lock(TB-1401B)to secure the azimuth-adjustment screw.2AC BIAS FREQUENCY ADJUSTMENTS( 1 ) Connect frequency counter to CN201(BS);( 2 ) R/P swith in recording state;( 3 ) Adjusting T201 use a plastic screwdriver, AC bias frepuency;62+-1KHZ.3TAPE SPEED ADJUSTMENT( 1 ) Insert the test tape(MTT-111N,3,000 HZ)( 2 ) Press the PLAY button.( 3 ) Use a flat-tip screwdriver to turn the MOTOR VRadjust MOTOR VR so that the frequency counterbecome 3,000HzCASSETTE MECHANISM SECTIONCASS DECKP/R HEADHEAD AZIMUTH ADJUSTING SCREW1-8RC-BX33SLTape recorder sectionItemsMeasurementMeasurement methodStandardAdjustingconditionsValuespositionsConfirmationTest tape1 Playback the test tape TCC-182A (8KHz)MaximumAdjust the headof head angle:TCC-182A(8KHz)2 With the recording & playback mechanism, outputazimuth screwMeasurement output adjust the head azimuth screw so that theonly terminal left and right output levers become:Speaker terminal maximum, After adjustment, lock theSparker R head azimuth at least by half turn.(Load resistance:8?):Headphone terminalConfirmationTest tapeAdjust VR401 so that the frequency counterTape speed MOTOR VRof tape speed:TCC-112(3KHz)reading becomes 3,010Hz +/-15Hz whenof deckMeasurement outputplaying back the test tape TCC-112 (3KHz):3,010Hzterminalwith playback and recording mechanism+/-15Hz:Headphone terminalafter ending forward winding of the tape.Reference Values for Confirmation ItemsITEMSMeasurementMeasurement methodStandardAdjustingconditionsValuespositionsWow & flutterTest tapeWhen the test tape TCC-112 (3KHz) has been 0.25% or:TCC-112(3KHz)played back with the recording and playbacklessmechanism at the beginning of forward(WRMS)Measurement outputwinding, the frequency counter reading ofterminalwow & flutter should be 0.25% or less:Headphone terminal(WRMS).1-9 RC-BX33SLElectrical PerformanceITEMSMeasurementMeasurement methodStandardAdjustingconditionsValuespositionsAdjustment of * Mode: PB mode1 With the recording and playback mechanism,recording bias * Recording mode load the test tapes TDK-D60, and set the TDK-D60current* Test tape: TDK-D60 mechanism to the recording and pausing4.5?A(Reference condition in advance . +/-0.5?AValue)* Measurement outputterminal2 After connecting 100ohms in series to the:Both recording and recorder head, measure the bias currentheadphone terminals with a valve voltmeter at both of the terminalsAdjustment of* Reference frequency 1 with the recording and playback mechanism,Output recording and:1KHz and 8KHz load the test tapes (TDK-D60) and set thedeviationplayback (REF.:- 10dB) mechanism to the recording and pausingbetweenfrequency* Test tape: TDK-D60 condition in advance.1KHz andcharacteristics8KHz* Measurement input2 While repetitively inputting the reference:-1dB +/-2dBterminal: OSC IN frequency signal of 1KHz and 8KHz from OSC IN, record and playback the tape.3 While receding and playback the test tape Lch and Rch so that the output deviation between 1KHz and 8KHz becomes -1dB +/-2dBReference Values for Electrical Function Confirmation ItemsItemsMeasurementMeasurement methodStandardAdjustingconditionsValuespositionsRecording* Playback1 While changing over to and form BIAS 162KHzT201bias* Test tape: TDK-D60 and 2, confirm that the frequency is+/-6KHzfrequency changed* Measurement2 With the recording and playbackterminal : BIAS TP on mechanism, load the test tape.P.C. board (TDK-D60 ) , and set the mechanism to the recording and pausing condition in advance.3 Confirm that the BIAS TP frequency on the P.C. board is 62KHz +/-6KHz1-10 RC-BX33SLFlow of functional operation until TOC read Check Point Check that the voltage at the pin 17 of CN901 is OV (a moment)? Check that the voltage at the pin1 of IC902 + side is + 5V?Confirm that the Focus errors-cuve signal at the pin16 ofIC902 is approx.2V p-pConfirm that the signal fromTE waveform at TOC readingpin14 IC902 is 0V as aaccelerated pulse duringapprox.400msConfirm the waveform ofthe Tracking error signalat the pin14 of IC902 (R926)(See fig-1)Confirm the eys-pattern at the lead of TP1Power KeySlider turns REST SW ON.Automatic tuningof TE offsetLaser ONDetection of discAuto tuning ofFocus offsetAuto. measurement of focus A-curve amplitudeDisc is rotatedFocus servo ON(Tracking servo ON)Auto. measurement ofTracking error amplitudeAutomatic tuning ofTracking error Automatic tuning ofFocus error balanceAutomatic tuning ofFocus error gainAutomatic tuning ofTracking error gainTOC readingPlay a discApprox 3secpin 25 ofIC601(TE)Approx1.8VTrackingservoTrackingservo on statuesDisc to bebraked to stopTOC readingfinishesDisc statusto rotateAuto measurementof TE amplitude and auto tuning of TE balance500mV/div2mS/div Fig.1VREF 1-11 TUNER ADJUSTMENTSuse a plastic screw driver for adjustments.Adjust the intermediate frequency of AM and FM to the frequency of ceramic filter.Supply voltage : DC 12.0 VSpeaker impedance : 8 OHMSFunction switch : RADIOa.AM