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1、SERVICE MANUAL RADIO CASSETTE RECORDER RC-W305 No: 28223 SEP. 2005 COPYRIGHT 2005 JVC ASIA PTE LTD Area Suffix U - Asia UX - Middle East SERVICE POLICY No service part is available for this model. Based on One to One exchange policy. Contents Safety Precaution.2 Preventing Static Electricity.3 Disas
2、sembly Method .4 Adjustment Method.5 Description Of Major IC.8 Voltage Charts.12 Wiring Connection Diagram.13 Schematic Diagram .14 Printed Circuit Board.15 RadioFans.CN 收音机爱 好者资料库 XL-SV320SL/SV305GD XL-SV308BU 2 RC-W305 1.This design of this product contains special hardware and many circuits and c
3、omponents specially for safety purposes. For continued protection, no changes should be made ti the original design unless authorised 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
4、. 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 manufacturer of responsibility for personal injury or property d
5、amage resulting 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 by them necessarily be obtain by using replaement components rated for high
6、er voltage, the Parts List 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 re
7、placement 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 temperatures parts, moving parts and/or sharp edges for the p
8、revention 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, after re-assembling. 5.Leakage current check (Electrical Shock hazard testing) After re-assembling the pro
9、duct, 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
10、this check. Plug the AC line cord directly into the AC outlet. Using a Leakage Current Tester, measure the leakage current from each ecposed metal parts of the cabinet, particularly and exposed metal part having a return path to the chassis, to a known good earth ground. Any leakage current must not
11、 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 sensitvity in the following manner. Connect a 1,500 ohm 10W resistor paralleled by a 0.15uF AC-type capacitor between an exposed metal part and
12、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 and exposed metal part having a return path to te chassis and measure the AC voltage across the resistor. Now, reverse the plug in the AC
13、 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 safe
14、ty 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. CAUTIONBurrs formed during moulding may be
15、 left over on some parts of the chassis. Therefore, pay attention to such burrs in the case of performing repair of this system. Safety Precautions Warning RadioFans.CN 收音机爱 好者资料库 RC-W305 3 Preventing static electricity Electrostatic discharge (ESD), which occurs when static electricity stored in th
16、e 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 electricity Static electricity in the work area can destroy the optical pickup in devicessuch. Be caref
17、ul to use proper grounding in the area where repairs are being performed. 1.1.1. Gound the workbench 1. 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. 1.1.2. Ground yourself 1.Use an an
18、ti-static wrist starp to release and static electricity built up in your body. XL-SV320SL/SV305GD XL-SV308BU 4 RC-W305 ? ? ? ? ? Disassembly Method Remove the back cabinet 1, Open the battery cover and remove 2 screws inside it. (Screw A) Screw A 2, Remove 5 screws on back side. (Screw B) Screw B Th
19、en the unit would be disassembled. RC-W305 5 ? ? ? ? ? Adjustment Method Instrument requiredPrecautions for alignment 1Direct connect to the IF sweeper output 1Low frequency oscillator side and 1 UF and 22 Kohm connect to the This oscillator should have a capacity to outputsweeper input side . Same
20、as FIG1 . 0dB to 600? at an oscillation frequency of 50Hz-20KHzIC101 PIN18 2Electronic voltmeter 3Distortion meter 4Frequency counter 5Wow & flutter meter 6Test tape2The IF sweeper output level should be made as TCC-112 : Tape speed and running unevenness (3KHz)low as possible within the adjustable
21、range . TCC-140 : Reference level (1KHz)3Since the IF sweeper is a fixed device , there is no TCC-182A : Head angle (8KHz) , playback frequencyneed to adjust this sweeper . characteristics (1KHz) and dubbing frequency4Since a ceramic oscillator is used , there is no need characteristics (125Hz and 8
22、KHz)to perform any MIX adjustment . 5Since a fixed coil is used , there is no need to 7Blank tapeadjust the FM tracking . TYPE I : TDK-D606The input and output earth systems are separated . In case of simultaneously measuring the voltage in 8Torque gauge : For play and back tensionboth of the input
23、and output systems with an FWD(CT-120m) , and FF/REW(CT-F)electronic voltmeter for two channels , therefore , the earth should be connected particularly carefully . General conditions 7 For connecting a dummy resistor when measuring the output , use the wire with a greater code size . Power supply v
24、oltage - RC-S20RC-S205 5( U ) AC 110V/220V 60Hz/50 8 Whenever any mixed tape is used , use the band Reference output - Speaker : 0.63V/8?pass filter (DV-12V) Headphone : 0.245V/32? playback characteristics Measurement output terminal - Speaker CN301 * Load resistance - 8? Tuner conditions AM frequen
25、cy - 400Hz AM modulation - 30% FM frequency - 1 KHz FM frequency deviation - 22.5KHz Reference measurement - 26.1mV(0.63V/8?) output Input positions - AM : Standard loop antenna FM : TP2 (hot) and TP3 (GND) Reference measurement - 26.1mV(0.63V/8?) output Input positions - AM : Standard loop antenna
26、FM : TP2 (hot) and TP3 (GND) XL-SV320SL/SV305GD XL-SV308BU 6 RC-W305 TUNER ADJUSTMENTSTUNER ADJUSTMENTS Use a plastic screw driver for adjustments. Adjust the intermediate frequency of AM and FM to the frequency of ceramic filter. Set of unit Use a plastic screw driver for adjustments. Adjust the in
27、termediate frequency of AM and FM to the frequency of ceramic filter. Set of unit Supply voltage : DC 9.0V Speaker impedance :8 ohms Standard output : 50 mW Function switch : RADIO a. Parts Location b. MW Adjustment a. Parts Location b. MW AdjustmentBand switch : MW Adjusting Connections SG Position
28、 ofVTVM CircuitlnputOutputFrequencyTuning dialOscilloscope Adjusting Connections SG Position ofVTVM CircuitlnputOutputFrequencyTuning dialOscilloscope Connect sweep 1 1IFgenerator to IC101 455KHzLowT102 (18)PIN(A) 2 2 TuningConnect AM SG toConnect VTVM to 515 KHz Low end T104 3 3 coverage loop ANTsp
29、eaker terminals. 1640 KHz High end TC102 4 4Connect AM SG toConnect VTVM to 600 KHz600 KHzMW ANT COIL 5 5 loop ANT speaker terminals1400 KHz1400 KHzPVC101-C3 c. SW Adjustmen c. SW Adjustmen t tBand switch : SW1 SW Dummy antenna : 75 ohms unbalance Adjusting Connections SGPosition ofVTVM Circuitlnput
30、OutputFrequencyTuning dialOscilloscope 1 Adjusting Connections SGPosition ofVTVM CircuitlnputOutputFrequencyTuning dialOscilloscope 1Tuning Connect AM SG toConnect VTVM to5.8 MHzLow end T105 2 2coverageFM ANT & D105(-)speaker terminals.15.4 MHzHigh end TC103 3 3Connect AM SG toConnect VTVM to7.0 MHz
31、7.0 MHz T107 4 4FM ANT &D105(-)speaker terminals.12.0 MHz16.0 MHzTC101 d. SW Adjustmen d. SW Adjustmen t tBand switch : SW2 SW Dummy antenna : 75 ohms unbalance Adjusting Connections SGPosition ofVTVM CircuitlnputOutputFrequencyTuning dialOscilloscope 1 Adjusting Connections SGPosition ofVTVM Circui
32、tlnputOutputFrequencyTuning dialOscilloscope 1Tuning Connect AM SG toConnect VTVM to14.8 MHzLow end T106 2 2coverageFM ANT & D105(-)speaker terminals.22.4 MHzHigh end TC104 3 3Connect AM SG toConnect VTVM to15.0 MHz15.0 MHz T108 4 4FM ANT &D105(-)speaker terminals.22.0 MHz22.0 MHzPVC101-C4 StepAdjus
33、tmentStepAdjustment Connect AM sweep generator to loop ANT. Max. Max. Tracking SteStep pAdjustmenAdjustmen Tracking Max. Max. TC102 TC103 TC104 T106 C1 T101 T107 C2 T105 T104 C4C3 L102L103T108TC101 T103T102 SteStep pAdjustmenAdjustmen Tracking Max. Max. RC-W305 7 e. FM Adjustment e. FM AdjustmentBan
34、d switch : FM FM Dummy antenna : 75 ohms unbalance Adjusting Connectionposition ofVTVM CircuitInputOutputtuning dialOscilloscope Adjusting Connectionposition ofVTVM CircuitInputOutputtuning dialOscilloscope Connect sweep 1 1IFgenerator to IC10110.7 MHzLowT101 T103 (18)PIN(A) 2 2Tuning Connect FM SG
35、toConnect VTVM to 87.4 MHzLow end L103 3 3coverageFM ANT & D105(-)speaker terminals.108.4 MHzHigh end PVC101-C1 4 4Connect FM SG toConnect VTVM to90.0 MHz90.0 MHz L102 5 5FM ANT &D105(-)speaker terminals.106.0 MHz106.0 MHzPVC101-C2 偩.TAPE DECK ADJUSTMENTS 1. HEAD REPLACEMENT After replacement, demag
36、netize. 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. 2. HEAD AZIMUTH ADJUSTMENT (1) Load the test tape(VTT-703, etc., 10 KHZ) for azimuth adjustment. (2) Press the
37、PLAY button. (3) Use a cross-tip screwdriver to turn the screw for azimuth 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. 3. MOTOR SPEED ADJUSTMENT (1) Ins
38、ert 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 become 3,000 HZ 4. CHECKING THE MECHANISM TORQUSE AND TENSION Clean the head, capstan and pinch roll
39、er making any measurement. MeasurementTake-up torqe Back tensionTape tension Drive-power cassette Cassette ofr PLAY:TW-211A PLAY: TW-2111A measurement F.FWD/REW:TW-2231 TW-2412 PLAY 30-60 gr.cm 2.0 - 4.5 gr. cm60 gr or more F.FWD 55-120 gr.cm - - REW 55-120 gr.cm - - StepSG FrequencyStepSG Frequency
40、 Tracking Max. Max. AdjustmentAdjustment Connect sweep generator to IC101(24)pin (B) XL-SV320SL/SV305GD XL-SV308BU 8 RC-W305 LA1824 Block Diagram ? ? ? ? ? Description of Major IC RC-W305 9 BA3308 Block Diagram XL-SV320SL/SV305GD XL-SV308BU 10 RC-W305 Block Diagram BA3416BL RC-W305 11 XL-SV320SL/SV3
41、05GD XL-SV308BU 12 RC-W305 ? ? ? ? ? Voltage Charts IC No. Item 12345678910111213141516171819 DC9V 0.041.313.044.374.37 0.004.370.10 2.841.30 1.300.174.37 3.653.661.221.22 1.261.39 Item 21222324 DC9V 4.344.34 0.000.29 IC No. Item 12345678910111213141516171819 DC9V 1.291.29 4.614.62 4.620.00 4.62 1.2
42、53.38 1.291.290.694.62 3.010.001.26 1.251.260.48 Item 21222324 DC9V 4.624.62 0.000.00 IC No. Item 12345678910111213141516171819 DC9V 1.291.29 4.594.61 4.610.00 4.61 1.233.351.29 1.290.554.61 3.000.001.261.25 1.260.40 Item 21222324 DC9V 4.614.61 0.000.00 IC No. Item 12345678910111213141516171819 DC9V
43、 1.291.29 4.61 4.634.630.00 4.631.213.38 1.291.290.57 4.633.020.0 1.261.25 1.260.41 Item 21222324 DC9V 4.634.630.000.00 IC No. Item 123456789101112 DC9V 10.035.12 9.201.190.00 10.030.000.00 1.199.185.1310.16 IC No. Item 123456789101112 DC9V 9.304.77 8.471.20 0.009.32 0.000.00 1.208.49 4.709.32 IC No
44、. Item 123456789101112131415161718 DC9V 0.990.00 0.000.00 2.16 2.145.501.875.13 1.070.00 1.310.590.590.00 0.000.000.00 IC No. Item 123456789101112131415161718 DC9V 0.060.00 0.000.00 2.16 2.155.50 0.675.14 1.070.001.310.59 0.590.000.000.00 0.00 IC No. Item 123456789 DC9V 0.950.00 0.920.46 0.00 0.000.
45、900.000.89 IC No. Item 123456789 DC9V 1.800.00 1.805.06 0.00 0.001.790.001.78 Transistor No. Item EBCEBC Votage(v) 6.106.80 9.356.106.809.05 IC303 LA-4227 CASS PLAY IC301 BA3416 B CASS PLAY IC302 BA3308 CASS REC Q401 (CASS PLAY) IC101 LA-1824 TUNER SW2 IC301 BA3416 A CASS PLAY Q401 (TUNER) IC101 LA-1824 TUNER FM IC101 LA-1824 TUNER AM IC101 LA-1824 TUNER SW1 IC303 LA-4227 TUNER IC302 BA3308 CASS PLAY RC-W305 13 ? ? ? ? ? Wiring Connections Diagram XL-SV320SL