Yamaha-TX497-tun-sm(1) 维修电路原理图.pdf

SERVICE MANUALThis manual has been provided for the use of authorized YAMAHA Retailers and their service personnel.It has been assumed that basic service procedures inherent to the industry, and more specifically YAMAHA Products, are alreadyknown and understood by the users, and have therefore not been restated.WARNING:Failure to follow appropriate service and safety procedures when servicing this product may result in personalinjury, destruction of expensive components, and failure of the product to perform as specified. For these reasons,we advise all YAMAHA product owners that any service required should be performed by an authorized YAMAHARetailer or the appointed service representative.IMPORTANT:The presentation or sale of this manual to any individual or firm does not constitute authorization, certification orrecognition of any applicable technical capabilities, or establish a principle-agent relationship of any form.The data provided is believed to be accurate and applicable to the unit(s) indicated on the cover. The research, engineering, and servicedepartments of YAMAHA are continually striving to improve YAMAHA products. Modifications are, therefore, inevitable andspecifications are subject to change without notice or obligation to retrofit. Should any discrepancy appear to exist, please contact thedistributors Service Division.WARNING:Static discharges can destroy expensive components. Discharge any static electricity your body may haveaccumulated by grounding yourself to the ground buss in the unit (heavy gauge black wires connect to this buss).IMPORTANT:Turn the unit OFF during disassembly and part replacement. Recheck all work before you apply power to the unit.IMPORTANT NOTICE100970SERVICE MANUALBLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . .19PRINTED CIRCUIT BOARD . . . . . . . . . . . . . . . . . . .20SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . .2122PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2331I CONTENTSTO SERVICE PERSONNEL . . . . . . . . . . . . . . . . . . . .2SPECIFICATIONS / . . . . . . . . . . . . . . . . . . . .3FRONT PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4REAR PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . .45INTERNAL VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6DISASSEMBLY PROCEDURES / . . . . . . . .6ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . .7111215IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16DISPLAY DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17AM/FM STEREO TUNERTX-497TX-497 2005 . All rights reserved.This manual is copyrighted by YAMAHA and may not be copied or redistributed either in print or electronically without permission.05.09RadioFans.CN 收音机爱 好者资料库2TX-497TX-497WARNING: CHEMICAL CONTENT NOTICE!The solder used in the production of this product contains LEAD. In addition, other electrical/electronic and /or plastic(where applicable) components may also contain traces of chemicals found by the California Health and Welfare Agency(and possibly other entities) to cause cancer and/or birth defects or other reproductive harm.DO NOT PLACE SOLDER, ELECTRICAL/ELECTRONIC OR PLASTIC COMPONENTS IN YOUR MOUTH FOR ANY REA-SON WHATSOEVER!Avoid prolonged, unprotected contact between solder and your skin! When soldering, do not inhale solder fumes or exposeeyes to solder/flux vapor!If you come in contact with solder or components located inside the enclosure of this product, wash your hands beforehandling food.TO SERVICE PERSONNELCritical Components Information.Components having special characteristics are markedand must be replaced with parts having specificationsequal to those originally installed.WALLOUTLETEQUIPMENTUNDER TESTAC LEAKAGETESTER OREQUIVALENTINSULATINGTABLEAbout leadfree solder / 無鉛The P.C.B.s installed in this unit are soldered using thefollowing solder.本機搭載基板付使用下記通。無鉛種類、修理時下記無鉛使用推奨。Sn+Ag+Cu（錫+銀+銅）Sn+Cu（錫+銅）Sn+Zn+Bi （錫+亜鉛+）注意： 無鉛融点温度通常鉛入比3040程度高、合使用。 鉛入使得場合、交換部品端子部周辺部無鉛取除、無鉛鉛入十分溶状態付。Among some types of lead free solder currently available,it is recommended to use one of the following types for therepair work.Sn + Ag + Cu (tin + silver + copper)Sn + Cu (tin + copper)Sn + Zn + Bi (tin + zinc + bismuth)Caution:1. As the melting point temperature of the lead free solderis about 30C to 40C (50F to 70F) higher than that ofthe lead solder, be sure to use a soldering iron suitableto each solder.2. If lead solder must be used, be sure to remove lead freesolder from each terminal section of the parts to bereplaced and from the area around it completely beforesoldering, or make sure that the lead-free solder andlead solder melt together fully.TUNER P.C.B.OPERATION P.C.B.Side A / A 面Side B / B 面Lead Free Solder / 無鉛Lead Free Solder / 無鉛Side ASide BSMTREFLOW ProcessMIFLOW ProcessSolder DipRadioFans.CN 收音机爱 好者资料库3TX-497TX-497 FM SECTION / FM部Tuning Range / 受信周波数範囲U, C models . 87.5 to 107.9 MHzR, T, A, B, G, E, L models . 87.50 to 108.00 MHzJ model . 76.0 to 90.0 MHz50dB Quieting Sensitivity / 50dB SN感度 (IHF)U, C, R, T,A, L, J modelsMono . 1.55 V(15.1 dBf)Stereo (1 kHz 100% MOD)21 V(37.7 dBf)Usable Sensitivity / 実用感度 (DIN)B, G, E modelsMono (S/N 26 dB) . 0.9 VStereo (S/N 46 dB) . 24 VImage Response Ratio / 妨害比U, C, R, T, J models . 40 dBA, B, G, E, L models . 80 dBIF Response Ratio / IF妨害比 .70 dBSpurious Response Ratio / 妨害比U, C, R, T, J models . 60 dBA, B, G, E, L models . 70 dBAlternate Channel Selectivity / 実行選択度U, C, R, T, J models . 85 dBA, B, G, E, L models Selectivity (two signals) 40 kHz Dev. 300 kHz . 70 dBSignal to Noise Ratio / 信号対雑音比 (DIN-Weighted 40 kHz)U, C, R, T, J modelsMono . 82 dBStereo . 76 dBA, B, G, E, L modelsMono . 75 dBStereo . 70 dBHarmonic Distortion / 歪率 (1 kHz)Mono . 0.1 %Stereo (B, G: 40 kHz Dev.) .0.2 %Stereo Separation / (1 kHz)B, G: 40 kHz Dev. . 50 dBFrequency Response / 周波数特性30 Hz to 13 kHz . 00.5 dB MW SECTION / AM部Tuning Range / 受信周波数範囲U, C, R models .530 to 1710 kHzT, A, B, G, E, L, J models . 531 to 1611 kHzUsable Sensitivity / 実用感度 . 200 V/mSelectivity / 選択度 . 32 dBSignal to Noise Ratio / 信号対雑音比 . 50 dBImage Response Ratio / 妨害比 . 40 dBSpurious Response Ratio / 妨害比 . 50 dBHarmanic Distortion / 歪率 . 0.3 % LW SECTIONTuning RangeB, G, E models . 153 to 288 kHzUsable SensitivityB, G, E models . 400 V/mSelectivityB, G, E models . 32 dBSignal to Noise RatioB, G, E models .50 dBImage Response RatioB, G, E models .40 dBSpurious Response RatioB, G, E models .50 dBHarmanic DistortionB, G, E models . 0.3 % AUDIO SECTION / 部Output Level / Impedance（出力電圧 / ）(Fixed)U, C, R, T, A, L, J modelsFM 100 % MOD 1 kHz . 900 mV/2.2 k-ohmsMW/AM/LW 30 % MOD 1 kHz .150 mV/2.2 k-ohmsB, G, E modelsFM 100 % MOD 1 kHz . 500 mV/2.2 k-ohmsMW/LW 30 % MOD 1 kHz .200 mV/2.2 k-ohms GENERAL / 総合Power Supply / 電源電圧U, C models . AC120V, 60HzR, L models . AC110 to 120V, 220 to 240V, 50/60HzT model . AC220V, 50HzA model .AC240V, 50HzB, G, E models .AC230V, 50HzJ model . AC100V, 50/60HzPower Consumption / 消費電力 .7 WDimensions / 寸法 (W x H x D) . 435 x 86 x 271mmWeight / 質量 . 3.2 kgFinish / 仕上Gold color .T, L, J modelsBlack color . U, C, R, A, B, G, L, E modelsTitanium color . R, B, G, L, E modelsAccessories / 付属品Indoor FM Antenna x 1AM Loop Antenna x 1Antenna Adapter x 1 (U, C models)75-ohm/300-ohm antenna adapter x 1 (B model)Audio Pin Cable256.6(10-1/8)13.4 (1/2)70(2-3/4)16(5/8)271(10-11/16)86(3-3/8)435(17-1/18) DIMENSIONSSPECIFICATIONS / 参考仕様* Specifications subject to change without notice.4TX-497TX-497FRONT PANELSU, C, R, T, A, L, J modelsB, G, E modelsU, C modelsR, L modelsREAR PANELS5TX-497TX-497A modelB, G, E modelsJ modelT model6TX-497TX-497DISASSEMBLY PROCEDURES / (Remove parts in the order as numbered.)1. Removal of Top Cover2. Removal of Front Panel Unita. Disconnect the connectors (CB3 and CB4). (Fig. 1.)b. Remove 3 screws (). (Fig. 1.). Screws () are identified with arrow marks ( ).c. Remove 2 screws (). (Fig. 1.)a. Remove 4 screws () and 2 screws (). (Fig. 1.)b. Slide the Top Cover rearward to remove it. (Fig. 1.)e. Remove the Front Panel Unit. (Fig. 1.)d. Unhook at 2 place (). (Fig. 1.)INTERNAL VIEWTuner P. C. BFront-end packOperation P. C. B. (2)Operation P. C. B. (3)Operation P. C. B. (1)Operation P. C. B. (4) (R, L models)rertt（番号順部品取外。）1. 外2. 外a. CB3CB4抜。 (Fi g. 1. )b. 3本外。 (Fi g. 1. ). 矢印（）刻印。c. 2本外。 (Fi g. 1. )a. 4本、2本外。 (Fi g. 1. )b. 後方取外。 (Fi g. 1. )e. 外。 (Fi g. 1. )d. 2所外。 (Fi g. 1. ) 分解手順Top CoverFront Panel Uni t 7TX-497TX-497FMSGOscilloscopeACVMDIST. MFMANTLROUTPUTGNDFMdummyantennaTunerP. C. B.FMSGOscilloscopeACVMDIST. MFMANTLRYLF-15(LPF)OUTPUTGNDFMdummyantennaTunerP. C. B.SSGFMSGOscilloscopeACVMDIST. MFMANTLROUTPUTGNDFMdummyantennaTunerP. C. B.oscillatorFMSGDCVMFMANTTP1TP2R51GNDFMdummyantennaTunerP. C. B.oscillatorADJUSTMENTS1. Before Adjustment(1)With the power turned on, wait for 5 minutes beforestarting adjustment so that operation becomes stable.(2)Adjust the OSC coil and IFT with insulated screwdriver.(3)Set the TUNING MODE to AUTO.(4)Decibel abbreviationsdB : Decibels above or below 1VExample :0dB = 1 v, 60dB = 1 mVX dB = (X + 11.2) dBfWhen substituting 60 for X,60 dB = 72.2 dBf2. Measuring instrument abbreviationsFM SG: FM signal generatorSSG: Stereo signal generatorAM SG: AM signal generatorDIST. M: Distortion meterFC: Frequency counterACVM: AC voltage meterDCVM: DC voltage meterRDS SG: RDS signal generatorCheck that the voltage obtained across each test pointand ground on the tuner circuit is as follows.Test pointsRating or Standard+5 V terminal+5.6 0.5 V-VP terminal-23.0 1.0 VCAUTION :Before setting to the TEST mode, write down the userpreset memory content in the table as shown below. (Thisis because setting to the TEST mode will cause thememory content to be the factory preset memory content,i.e. all the user preset memory content will be erased.)Preset keysP1P2P3P4P5P6P7P8ABCDETurn on the POWER switch while pressing the A/B/C/D/E and FM/AM(FM/MW/LW) keys simultaneously, andthe unit enters the TEST mode for the display check.After this, repeat (1) to (4).(1)All the segments on the display light up.(2)The model name, TX-497 is displayed.(3)The place of destination is displayed.(4)The COM-version is displayed.Pressing the P1 key will cause operation to start from (1).Pressing any other key will cause the mode to return to theNORMAL mode.B, G, E modelsPresetP1P2P3P4P5P6P7P8A, E87.5090.1095.1098.10108.0088.10106.10 108.00B, D63010801440531171190013501400C1531712252702881802072521) Discriminator balance adjustment2) Monaural distortion adjustment3) Stereo distortion adjustment4) Sensitivity verificationA, L, R modelsPresetP1P2P3P4P5P6P7P8A, C, E87.5090.1095.1098.10108.0088.10106.10 108.00B, D63010801440531161190013501404U, C modelsPresetP1P2P3P4P5P6P7P8A, C, E87.590.195.198.1107.988.1106.1107.9B, D630108014405301710900135014008TX-497TX-497TEST POINTSAdjustment itemRough adjustment ofdiscriminator balance.Rough adjustment ofmonaural distortion.Fine adjustment ofdiscriminator balance.Fine adjustment ofmonaural distortion.Verification ofdiscriminator balance.Adjustment of frontendIFT.Adjustment of stereodistortion.Step1234567Signal (ANT IN)FM SG:98.1 MHz 70 dBModulation : 100 %Monaural : 1 kHzSame as Step 1.Same as Step 1.Same as Step 1.Same as Step 1.FM SG:98.1 MHz 30 dBModulation : 100 %Monaural : 1 kHzFM SG:98.1 MHz 70 dBModulation : 100 %Stereo L or R : 1 kHzAdjustedpointL8(right side)L8(left side)L8(right side)L8(left side)FrontendIFTVR1, VR2ReceptionfrequencyPresetA-4: 98.1 MHzSame as Step 1.Same as Step 1.Same as Step 1.Same as Step 1.Same as Step 1.Same as Step 1.RatingDC 0 V 100mVat tuning point.Minimize distortion.DC 0 V 50mVMinimize distortion.(to less than 0.7%)DC 0 V 50mVAdjust so that theDC voltage ismaximum.CAUTION:If IFT core is turnedexcessively, thesensitivity reduces. (Maximum 90)Minimize distortion.Tuning mode isAUTO.Test pointTP1, TP2(both endof R51)OUTPUTTP1, TP2OUTPUTTP1, TP2TP3, GNDOUTPUTLI NE OUTAM ANT GNDFM ANTLRL13 L12 VR4VR3R51J6J7VR2VR1L10L5L8PK2PK1J73TP2TP1TP3J108GNDBALANCEDISCRIMINATORDISTORTIONMONAURALFRONTENDIFTDISTORTIONSTEREOAM SENSITIVITYSEPARATIONMETERSIGNAL9TX-497TX-497Adjustment itemVerification of monauraldistortion.Verification of stereodistortion.Verification ofsensitivity.Adjustment ofseparation.Adjustment of the signalmeter.Verification of the signalmeter to turn off.Verification of AUTOTUNING.Ste891011121314Signal (ANT IN)FM SG:98.1 MHz 70 dBModulation : 100 %Monaural : 1 kHzFM SG:98.1 MHz 70 dBModulation : 100 %Stereo L or R : 1 kHzFM SG:88.1/98.1/106.1 MHzModulation : 100 %Monaural : 1 kHzFM SG:98.1 MHz 70 dBModulation : 100 %Stereo L or R : 1 kHzFM SG:98.1 MHz 45 dBModulation : 30 %Monaural : 1 kHzANT input minimum.FM SG:98.1 MHz 23 dBModulation : 30 %Stereo L or R : 1 kHzAdjustedpointVR4VR3TuningbuttonsReceptionfrequencySame as Step 1.Same as Step 1.A-6: 88.1 MHzA-4: 98.1 MHzA-7: 106.1 MHzPresetA-4: 98.1 MHzPresetA-4: 98.1 MHzPresetA-4: 98.1 MHzRatingMinimize distortion.(to less than 0.7%)Minimize distortion.(to less than 1.4%)Tuning mode isAUTO.S/N should be 30 dBat each frequency of88.1 MHz, 98.1 MHzand 106.1 MHz.Make sure that thevoltage at the ANTterminal is 3 dB (7dB at A, B, G, Emodels) or less.To more than 35 dB.Tuning mode isAUTO.Adjust so that thesignal meter ismaximum at ratinglevel.Make sure that thesignal meter isturned off.Automatic receptionshould be availablewhen the tuning UPor DOWN key ispressed.Stereo indicator isturned on.Audio muting shouldbe applied duringtuning.Verification of AUTO PS(program service name)B, G, E models only15RDS SG:Modulation : 1.6 %(1.2 kHz)FM SG:98.1 MHz 40 dBModulation : 100 %Monaural : 1 kHzPresetA-4: 98.1 MHzMake sure that thedisplay automaticallyturns to the PSmode and PSindicator turns onwhen the signal istuned again.Test pointOUTPUTOUTPUTOUTPUTSignalmeter10TX-497TX-497To be adjusted after FM section adjustment.Use the specified dummy anetenna for loop antenna.Adjustment itemAdjustment ofsensitivity.Verification ofsensitivity.Verification of the signalmeter.Verification of autotuning.Step1234Signal (ANT IN)AM SG:630 kHz 50 dB,1 kHz,30% modulationAM SG:630 kHz/1080 kHz/1440 kHz 50 dB,1 kHz,30% modulationAM SG:1080 kHz 90 dB,ANT input 90 dBANT input -10 dB orlessAM SG:1080 kHz 60 dB,1 kHz,30% modulationAdjustedpointL5TuningbuttonReceptionfrequencyPresetB-1: 630 kHzPresetB-1: 630 kHzB-2: 1080 kHzB-3: 1440 kHzPresetB-2: 1080 kHzPresetB-2: 1080 kHzRatingMaximize detectedsignal output.To be less than 54dB.Make sure that thesignal meter isturned on.Make sure that thesignal meter isturned off.Automatic receptionshould be availablewhen the tuning UPor DOWN key ispressed.Audio muting shouldbe applied duringtuning.Test pointOUTPUTAMSGAM ANTGNDAM dummy antennaAM loop antenna11TX-497TX-497Adjustment itemVerification ofsensitivity.Verification of the signalmeter.Verification of autotuning.Step123Signal (ANT IN)AM SG:171 kHz/225 kHz/270kHz 90 dB,1 kHz,30% modulationAM SG:225 kHz 90 dB,ANT input 90 dB