Jvc-RCW-305-Service-Manual电路原理图.pdf

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1、SERVICE MANUALRADIO CASSETTE RECORDERRC-W305No: 28223SEP. 2005COPYRIGHT 2005 JVC ASIA PTE LTDArea SuffixU - AsiaUX - Middle EastSERVICE POLICYNo service part is available for this model.Based on One to One exchange policy.ContentsSafety Precaution .2Preventing Static Electricity.3Disassembly Method

2、.4Adjustment Method.5Description Of Major IC .8Voltage Charts.12Wiring Connection Diagram .13Schematic Diagram .14Printed Circuit Board .15XL-SV320SL/SV305GDXL-SV308BU2RC-W3051. This design of this product contains special hardware and many circuits and components specially forsafety purposes. For c

3、ontinued 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

4、product should not be made. Any design alterations of the product should not be made. Any design alterations or additions will void the manufacturers warrantyand will further relieve the manufacturer of responsibility for personal injury or property damageresulting therefrom.3. Many eletrical and me

5、chanical 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. Electri

6、cal 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 substituterepalcement which does not have the same safety characteristics as the recommended replacement parts shown in the Parts List of Service man

7、ual 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 temperatures parts, moving parts and/or sharp edges for the prevention of electric shcok and fire hazard. When serv

8、ice 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 m

9、etap 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 outl

10、et. 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 l

11、ine 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 resis

12、tor 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

13、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

14、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 bu

15、rrs in the case of performing repair of this system.Safety PrecautionsWarningRC-W3053Preventing 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

16、 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 in devicessuch.Be careful to use proper grounding in the area where repairs are being performed.1.1.1. Gound the workbench1. Ground t

17、he 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.XL-SV320SL/SV305GDXL-SV308BU4RC-W305

18、 Disassembly MethodRemove the back cabinet1, Open the battery cover and remove 2 screws inside it. (Screw A)Screw A2, Remove 5 screws on back side. (Screw B)Screw BThen the unit would be disassembled.RC-W3055 Adjustment MethodInstrument required Precautions for alignment1 Direct connect to the IF sw

19、eeper output1 Low frequency oscillator side and 1 UF and 22 Kohm connect to the This oscillator should have a capacity to output sweeper input side . Same as FIG1 .0dB to 600g1256 at an oscillation frequency of50Hz-20KHz IC101PIN182 Electronic voltmeter3 Distortion meter4 Frequency counter5 Wow & fl

20、utter meter6 Test tape 2 The IF sweeper output level should be made asTCC-112 : Tape speed and running unevenness (3KHz) low as possible within the adjustable range .TCC-140 : Reference level (1KHz) 3 Since the IF sweeper is a fixed device , there is no TCC-182A : Head angle (8KHz) , playback freque

21、ncy need to adjust this sweeper .characteristics (1KHz) and dubbing frequency 4 Since a ceramic oscillator is used , there is no needcharacteristics (125Hz and 8KHz) to perform any MIX adjustment . 5 Since a fixed coil is used , there is no need to 7 Blank tape adjust the FM tracking .TYPE I : TDK-D

22、60 6 The input and output earth systems are separated .In case of simultaneously measuring the voltage in8 Torque gauge : For play and back tension both of the input and output systems with anFWD(CT-120m) , and FF/REW(CT-F) electronic voltmeter for two channels , therefore , the earth should be conn

23、ected particularly carefully .General conditions 7 For connecting a dummy resistor when measuring the output , use the wire with a greater code size .Power supply voltage - RC-S205( U ) AC 110V/220V 60Hz/50 8 Whenever any mixed tape is used , use the band Reference output - Speaker : 0.63V/8g1256 pa

24、ss filter (DV-12V)Headphone : 0.245V/32g1256playback characteristicsMeasurement output terminal - Speaker CN301* Load resistance - 8g1256Tuner conditionsAM frequency - 400HzAM modulation - 30%FM frequency - 1 KHzFM frequency deviation - 22.5KHzReference measurement - 26.1mV(0.63V/8g1256)outputInput

25、positions - AM : Standard loop antennaFM : TP2 (hot) and TP3 (GND)Reference measurement - 26.1mV(0.63V/8g1256)outputInput positions - AM : Standard loop antennaFM : TP2 (hot) and TP3 (GND)XL-SV320SL/SV305GDXL-SV308BU6RC-W305TUNER ADJUSTMENTSUse a plastic screw driver for adjustments.Adjust the inter

26、mediate frequency of AM and FM to the frequency of ceramic filter.Set of unitSupply voltage : DC 9.0VSpeaker impedance :8 ohms Standard output : 50 mW Function switch : RADIOa. Parts Locationb. MW Adjustment Band switch : MWAdjusting Connections SGPosition of VTVMCircuit lnput Output Frequency Tunin

27、g dial OscilloscopeConnect sweep1 IF generator to IC101 455KHz Low T102(18)PIN(A) 2Tuning Connect AM SG to Connect VTVM to 515 KHz Low end T1043 coverage loop ANT speaker terminals. 1640 KHz High end TC1024 Connect AM SG to Connect VTVM to 600 KHz 600 KHz MW ANT COIL5 loop ANT speaker terminals 1400

28、 KHz 1400 KHz PVC101-C3c. SW Adjustment Band switch : SW1 SW Dummy antenna : 75 ohms unbalanceAdjusting Connections SG Position of VTVMCircuit lnput Output Frequency Tuning dial Oscilloscope1 Tuning Connect AM SG to Connect VTVM to 5.8 MHz Low end T1052 coverage FM ANT & D105(-) speaker terminals. 1

29、5.4 MHz High end TC1033 Connect AM SG to Connect VTVM to 7.0 MHz 7.0 MHz T1074 FM ANT &D105(-) speaker terminals. 12.0 MHz 16.0 MHz TC101d. SW Adjustment Band switch : SW2 SW Dummy antenna : 75 ohms unbalanceAdjusting Connections SG Position of VTVMCircuit lnput Output Frequency Tuning dial Oscillos

30、cope1 Tuning Connect AM SG to Connect VTVM to 14.8 MHz Low end T1062 coverage FM ANT & D105(-) speaker terminals. 22.4 MHz High end TC1043 Connect AM SG to Connect VTVM to 15.0 MHz 15.0 MHz T1084 FM ANT &D105(-) speaker terminals. 22.0 MHz 22.0 MHz PVC101-C4Step AdjustmentConnect AM sweepgenerator t

31、o loopANT.Max.Max.TrackingStep AdjustmenTrackingMax.Max.TC102TC103TC104T106C1T101T107C2T105T104C4C3L102 L103T108TC101T103T102Step AdjustmenTrackingMax.Max.RC-W3057e. FM Adjustment Band switch : FM FM Dummy antenna : 75 ohms unbalanceAdjusting Connection position of VTVMCircuit Input Output tuning di

32、al OscilloscopeConnect sweep1 IF generator to IC101 10.7 MHz Low T101_ T103(18)PIN(A) 2 Tuning Connect FM SG to Connect VTVM to 87.4 MHz Low end L1033 coverage FM ANT & D105(-) speaker terminals. 108.4 MHz High end PVC101-C14 Connect FM SG to Connect VTVM to 90.0 MHz 90.0 MHz L1025 FM ANT &D105(-) s

33、peaker terminals. 106.0 MHz 106.0 MHz PVC101-C2( .TAPE DECK ADJUSTMENTS1. HEAD REPLACEMENTAfter replacement, demagnetize. the heads by using a degausser. Be sure to clean the head before attempting to make any adjustments.All wiring should be returned to the original position after work is completed

34、.2. HEAD AZIMUTH ADJUSTMENT(1) Load the test tape(VTT-703, etc., 10 KHZ) for azimuthadjustment. (2) Press the PLAY button.(3) Use a cross-tip screwdriver to turn the screw for azimuthadjustment so that the left and right output are maximized(4) Press the STOP button.(5) After completion of the adjus

35、tment, use thread lock(TB-1401B)to secure the azimuth-adjustment screw.3. MOTOR SPEED ADJUSTMENT(1) Insert the test tape(MTT-111N, etc., 3,000 HZ)(2) Press the PLAY button.(3) Use a flat-tip screwdriver to turn the SVR(located inside the rear of the motor) to adjust SVR so that the frequency counter

36、become 3,000 HZ4. CHECKING THE MECHANISM TORQUSE AND TENSIONClean the head, capstan and pinch roller making any measurement.Measurement Take-up torqe Back tension Tape tensionDrive-power cassetteCassette ofr PLAY:TW-211A PLAY: TW-2111Ameasurement F.FWD/REW:TW-2231 TW-2412PLAY 30-60 gr.cm 2.0 - 4.5 g

37、r. cm 60 gr or moreF.FWD 55-120 gr.cm - -REW 55-120 gr.cm - -Step SG FrequencyTrackingMax.Max.AdjustmentConnect sweepgenerator toIC101(24)pin (B)XL-SV320SL/SV305GDXL-SV308BU8RC-W305LA1824 Block Diagram Description of Major ICRC-W3059BA3308 Block DiagramXL-SV320SL/SV305GDXL-SV308BU10RC-W305Block DiagramBA3416BL