Yamaha-TX-497-Service-Manual(1) 电路图 维修手册.pdf

《Yamaha-TX-497-Service-Manual(1) 电路图 维修手册.pdf》由会员分享，可在线阅读，更多相关《Yamaha-TX-497-Service-Manual(1) 电路图 维修手册.pdf（32页珍藏版）》请在收音机爱好者资料库上搜索。

1、SERVICE MANUAL This 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 already known and understood by the users, and have therefore no

2、t been restated. WARNING:Failure to follow appropriate service and safety procedures when servicing this product may result in personal injury, destruction of expensive components, and failure of the product to perform as specified. For these reasons, we advise all YAMAHA product owners that any ser

3、vice required should be performed by an authorized YAMAHA Retailer or the appointed service representative. IMPORTANT:The presentation or sale of this manual to any individual or firm does not constitute authorization, certification or recognition of any applicable technical capabilities, or establi

4、sh 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 service departments of YAMAHA are continually striving to improve YAMAHA products. Modifications are, therefore, inevitable

5、 and specifications are subject to change without notice or obligation to retrofit. Should any discrepancy appear to exist, please contact the distributors Service Division. WARNING:Static discharges can destroy expensive components. Discharge any static electricity your body may have accumulated by

6、 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 NOTICE 100970 SERVICE MANUAL BLOCK DIAGRAM . . . . . . . . . . . . .

7、. . . . . . . . . . . . . .19 PRINTED CIRCUIT BOARD . . . . . . . . . . . . . . . . . . .20 SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . .2122 PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2331 I CONTENTS TO SERVICE PERSONNEL . . . . . . . . . . . . . . . . . . . .2 SP

8、ECIFICATIONS / . . . . . . . . . . . . . . . . . . . .3 FRONT PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 REAR PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 INTERNAL VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 DISASSEMBLY PROCEDURES / . .

9、. . . . . .6 ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . .711 1215 IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 DISPLAY DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 AM/FM STEREO TUNER TX-497 TX-497 2005 . All rights reserved.

10、 This manual is copyrighted by YAMAHA and may not be copied or redistributed either in print or electronically without permission. 05.09 RadioFans.CN 收音机爱 好者资料库 2 TX-497 TX-497 WARNING: CHEMICAL CONTENT NOTICE! The solder used in the production of this product contains LEAD. In addition, other elect

11、rical/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 C

12、OMPONENTS 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 expose eyes to solder/flux vapor! If you come in contact with solder or components located inside the enclosure of this product, wash

13、your hands before handling food. TO SERVICE PERSONNEL Critical Components Information. Components having special characteristics are marked and must be replaced with parts having specifications equal to those originally installed. WALL OUTLET EQUIPMENT UNDER TEST AC LEAKAGE TESTER OR EQUIVALENT INSU

14、LATING TABLE About leadfree solder / 無鉛 The P.C.B.s installed in this unit are soldered using the following 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30 40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 cu

15、rrently available, it is recommended to use one of the following types for the repair 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 solder is about 30C to 40C (50F to 70F) higher tha

16、n that of the lead solder, be sure to use a soldering iron suitable to each solder. 2. If lead solder must be used, be sure to remove lead free solder from each terminal section of the parts to be replaced and from the area around it completely before soldering, or make sure that the lead-free solde

17、r and lead 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 A Side B SMTREFLOW Process MIFLOW Process Solder Dip RadioFans.CN 收音机爱 好者资料库 3 TX-497 TX-497 FM SECTION / FM部 Tuning Range / 受信周波数範囲 U, C models . 87.5 to 1

18、07.9 MHz R, T, A, B, G, E, L models . 87.50 to 108.00 MHz J model . 76.0 to 90.0 MHz 50dB Quieting Sensitivity / 50dB SN感度 (IHF) U, C, R, T,A, L, J models Mono . 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 models Mono (S/N 26 dB) . 0.9 V Stereo (S/N

19、 46 dB) . 24 V Image Response Ratio / 妨害比 U, C, R, T, J models . 40 dB A, B, G, E, L models . 80 dB IF Response Ratio / IF妨害比 .70 dB Spurious Response Ratio / 妨害比 U, C, R, T, J models . 60 dB A, B, G, E, L models . 70 dB Alternate Channel Selectivity / 実行選択度 U, C, R, T, J models . 85 dB A, B, G, E,

20、L models Selectivity (two signals) 40 kHz Dev. 300 kHz . 70 dB Signal to Noise Ratio / 信号対雑音比 (DIN-Weighted 40 kHz) U, C, R, T, J models Mono . 82 dB Stereo . 76 dB A, B, G, E, L models Mono . 75 dB Stereo . 70 dB Harmonic Distortion / 歪率 (1 kHz) Mono . 0.1 % Stereo (B, G: 40 kHz Dev.) .0.2 % Stereo

21、 Separation / (1 kHz) B, G: 40 kHz Dev. . 50 dB Frequency 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 kHz T, A, B, G, E, L, J models . 531 to 1611 kHz Usable Sensitivity / 実用感度 . 200 V/m Selectivity / 選択度 . 32 dB Signal to Noise Rati

22、o / 信号対雑音比 . 50 dB Image Response Ratio / 妨害比 . 40 dB Spurious Response Ratio / 妨害比 . 50 dB Harmanic Distortion / 歪率 . 0.3 % LW SECTION Tuning Range B, G, E models . 153 to 288 kHz Usable Sensitivity B, G, E models . 400 V/m Selectivity B, G, E models . 32 dB Signal to Noise Ratio B, G, E models .50

23、 dB Image Response Ratio B, G, E models .40 dB Spurious Response Ratio B, G, E models .50 dB Harmanic Distortion B, G, E models . 0.3 % AUDIO SECTION / 部 Output Level / Impedance （出力電圧 / ）(Fixed) U, C, R, T, A, L, J models FM 100 % MOD 1 kHz . 900 mV/2.2 k-ohms MW/AM/LW 30 % MOD 1 kHz .150 mV/2.2 k-

24、ohms B, G, E models FM 100 % MOD 1 kHz . 500 mV/2.2 k-ohms MW/LW 30 % MOD 1 kHz .200 mV/2.2 k-ohms GENERAL / 総合 Power Supply / 電源電圧 U, C models . AC120V, 60Hz R, L models . AC110 to 120V, 220 to 240V, 50/60Hz T model . AC220V, 50Hz A model .AC240V, 50Hz B, G, E models .AC230V, 50Hz J model . AC100V,

25、 50/60Hz Power Consumption / 消費電力 .7 W Dimensions / 寸法 (W x H x D) . 435 x 86 x 271mm Weight / 質量 . 3.2 kg Finish / 仕上 Gold color .T, L, J models Black color . U, C, R, A, B, G, L, E models Titanium color . R, B, G, L, E models Accessories / 付属品 Indoor FM Antenna x 1 AM Loop Antenna x 1 Antenna Adap

26、ter x 1 (U, C models) 75-ohm/300-ohm antenna adapter x 1 (B model) Audio Pin Cable 256.6 (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) DIMENSIONS SPECIFICATIONS / 参考仕様 * Specifications subject to change without notice. RadioFans.CN 收音机爱 好者资料库 4 TX-497 TX-497 FRONT P

27、ANELS U, C, R, T, A, L, J models B, G, E models U, C models R, L models REAR PANELS 5 TX-497 TX-497 A model B, G, E models J model T model 6 TX-497 TX-497 DISASSEMBLY PROCEDURES / (Remove parts in the order as numbered.) 1. Removal of Top Cover 2. Removal of Front Panel Unit a. Disconnect the connec

28、tors (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. Unho

29、ok at 2 place (). (Fig. 1.) INTERNAL VIEW Tuner P. C. B Front-end pack Operation P. C. B. (2) Operation P. C. B. (3) Operation P. C. B. (1) Operation P. C. B. (4) (R, L models) r e r t t （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.

30、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 Cover Front Panel Uni t 7 TX-497 TX-497 FM SG Oscilloscope ACVM DIST. M FM ANT L R OUT PUT GND FM dummy antenna Tuner P. C. B. FM SG Oscilloscope ACVM DIST. M FM ANT L R YLF-15 (LPF) OUT PUT GND FM dummy antenna Tuner P. C. B.

31、SSG FM SG Oscilloscope ACVM DIST. M FM ANT L R OUT PUT GND FM dummy antenna Tuner P. C. B. oscillator FM SG DCVM FM ANT TP1 TP2 R51 GND FM dummy antenna Tuner P. C. B. oscillator ADJUSTMENTS 1. Before Adjustment (1)With the power turned on, wait for 5 minutes before starting adjustment so that opera

32、tion becomes stable. (2)Adjust the OSC coil and IFT with insulated screwdriver. (3)Set the TUNING MODE to AUTO. (4)Decibel abbreviations dB : Decibels above or below 1V Example : 0dB = 1 v, 60dB = 1 mV X dB = (X + 11.2) dBf When substituting 60 for X, 60 dB = 72.2 dBf 2. Measuring instrument abbrevi

33、ations FM SG: FM signal generator SSG: Stereo signal generator AM SG: AM signal generator DIST. M: Distortion meter FC: Frequency counter ACVM: AC voltage meter DCVM: DC voltage meter RDS SG: RDS signal generator Check that the voltage obtained across each test point and ground on the tuner circuit

34、is as follows. Test pointsRating or Standard +5 V terminal+5.6 0.5 V -VP terminal-23.0 1.0 V CAUTION : Before setting to the TEST mode, write down the user preset memory content in the table as shown below. (This is because setting to the TEST mode will cause the memory content to be the factory pre

35、set memory content, i.e. all the user preset memory content will be erased.) Preset keysP1P2P3P4P5P6P7P8 A B C D E Turn on the POWER switch while pressing the A/B/C/D/ E and FM/AM(FM/MW/LW) keys simultaneously, and the unit enters the TEST mode for the display check. After this, repeat (1) to (4). (

36、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 the NORMAL mode. B, G, E

37、models PresetP1P2P3P4P5P6P7P8 A, E87.5090.1095.1098.10108.0088.10106.10 108.00 B, D63010801440531171190013501400 C153171225270288180207252 1) Discriminator balance adjustment 2) Monaural distortion adjustment 3) Stereo distortion adjustment 4) Sensitivity verification A, L, R models PresetP1P2P3P4P5

38、P6P7P8 A, C, E87.5090.1095.1098.10108.0088.10106.10 108.00 B, D63010801440531161190013501404 U, C models PresetP1P2P3P4P5P6P7P8 A, C, E87.590.195.198.1107.988.1106.1107.9 B, D63010801440530171090013501400 8 TX-497 TX-497 TEST POINTS Adjustment item Rough adjustment of discriminator balance. Rough ad

39、justment of monaural distortion. Fine adjustment of discriminator balance. Fine adjustment of monaural distortion. Verification of discriminator balance. Adjustment of frontend IFT. Adjustment of stereo distortion. Step 1 2 3 4 5 6 7 Signal (ANT IN) FM SG: 98.1 MHz 70 dB Modulation : 100 % Monaural

40、: 1 kHz Same as Step 1. Same as Step 1. Same as Step 1. Same as Step 1. FM SG: 98.1 MHz 30 dB Modulation : 100 % Monaural : 1 kHz FM SG: 98.1 MHz 70 dB Modulation : 100 % Stereo L or R : 1 kHz Adjusted point L8 (right side) L8 (left side) L8 (right side) L8 (left side) Frontend IFT VR1, VR2 Receptio

41、n frequency Preset A-4: 98.1 MHz Same as Step 1. Same as Step 1. Same as Step 1. Same as Step 1. Same as Step 1. Same as Step 1. Rating DC 0 V 100mV at tuning point. Minimize distortion. DC 0 V 50mV Minimize distortion. (to less than 0.7%) DC 0 V 50mV Adjust so that the DC voltage is maximum. CAUTIO

42、N: If IFT core is turned excessively, the sensitivity reduces. (Maximum 90) Minimize distortion. Tuning mode is AUTO. Test point TP1, TP2 (both end of R51) OUTPUT TP1, TP2 OUTPUT TP1, TP2 TP3, GND OUTPUT LI NE OUTAM ANT GNDFM ANT LR L13 L12 VR4 VR3 R51 J6 J7 VR2 VR1 L10 L5 L8 PK2 PK1 J73 TP2 TP1 TP3

43、 J108 GND BALANCE DISCRIMINATOR DISTORTION MONAURAL FRONTEND IFT DISTORTION STEREO AM SENSITIVITY SEPARATION METER SIGNAL 9 TX-497 TX-497 Adjustment item Verification of monaural distortion. Verification of stereo distortion. Verification of sensitivity. Adjustment of separation. Adjustment of the signal meter. Verification of the signal meter to turn off. Veri