Sony-STSB920-tun-sm 电路图 维修手册.pdf

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1、ST-SB920 AEP Model UK Model SERVICE MANUAL FM STEREO FM-AM TUNER MICROFILM SPECIFICATIONS FM tuner section Frequency range87.5 108.0 MHz Aerial terminals75 , unbalanced Intermediate frequency10.7 MHz Sensitivityat 26 dB quieting (mono) 10.3 dBf, 0.9 V/75 at 46 dB quieting (stereo) 38.5 dBf, 23 V/75

2、Usable sensitivity (IHF)10.3 dBf, 0.9 V/75 S/Nat 40 kHz deviation 80 dB (mono), 76 dB (stereo) Harmonic distortionWIDE 0.035 % (mono), 0.045 (stereo) NARROW 0.055 % (mono), 0.075 (stereo) Frequency response30 Hz 15 kHz (+0.3/0.7 dB) Separation50 dB at 1 kHz Selectivityat 400 kHz WIDE 85 dB NARROW 90

3、 dB at 300 kHz WIDE 45 dB NARROW 70 dB Outputat 40 kHz deviation 600 mV AM tuner section Frequency rangeMW: 522 1,611 kHz (9 kHz step) LW: 144 288 kHz (1 kHz step) Intermediate frequency450 kHz Usable Sensitivity(with AM loop aerial) MW: 200 V/m LW: 700 V/m Signal-to-noise ratioMW: 54 dB (50 mV/m, 9

4、99 kHz) LW: 50 dB (50 mV/m, 216 kHz) Harmonic distortion0.3% (50 mV/m, 400 Hz) Selectivity50 dB General Power requirements220 230 V, AC 50/60 Hz Power consumption12 W Input impedance75 Input connectorIEC-male Dimensions430 86 295 mm (w/h/d) Weight3.95 Supplied accessoriesAudio cord (1) AM loop aeria

5、l (1) FM wire aerial (1) EON connecting cord (1) Design and specifications are subject to change without notice. RadioFans.CN 收音机爱 好者资料库 2 1.GENERAL2 2.TEST MODE3 3.ELECTRICAL ADJUSTMENT5 4.DIAGRAMS 4-1.Circuit Board Location 8 4-2.Schematic Diagram DISPLAY SECTION 9 4-3.Printed Wiring Board DISPLAY

6、 SECTION 11 4-4.Printed Wirng Board TUNER SECTION 13 4-5.Schematic Diagram TUNER SECTION (1/2) 15 4-6.Schematic Diagram TUNER SECTION (2/2) 17 4-7.IC Pin Function 19 4-8.IC Block Diagram 20 6.EXPLODED VIEWS 6-1.Front Panel and Case Section 21 6-2.Panel and Display Section 22 7.ELECTRICAL PARTS LIST2

7、3 TABLE OF CONTENTS SECTION 1 GENERAL SAFETY-RELATED COMPONENT WARNING! COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINE WITH MARK ! ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUA

8、L OR IN SUPPLEMENTS PUBLISHED BY SONY. PARTS No.MODEL MODEL IDENTIFICATION BACK PANEL 4-998-494-0 4-998-494-1 AEP model UK model ?yyyyyyyy PART NO. 1POWER swtich (U) 2SHIFT button 3Numeric button 4Display window 5DIRECT button 6TUNING/SELECT knob 7DISPLAY button 8PTY button 9TA button 0NEWS/INFO but

9、ton !AUTO-BETICAL SELECT button 123546 7890! Location of Controls !MEMORY button !BAND button !ON/OFF button !ANTENNA button !FM MODE button !CHARACTER button !MENU button !RETURN button ENTER button TUNING MODE button RadioFans.CN 收音机爱 好者资料库 3 SECTION 2 TEST MODE 1. Circuit Check Mode Set to the re

10、ception frequency that the curcuit can STEREO RDS stations. (Set the input level to above 70 dB.) This enables circuit check to be performed in any of the reception modes-FM, AM (MW, LW). Set to a desired band before setting the test mode. 1.Turn OFF the power. 2.While pressing 4 and AUTO-BETICAL SE

11、LECT together, turn ON U . The items in the following table will be checked automatically in order every 2 seconds. Display Tuned IF Frq Sig Level Stereo RDS Signal Items AST signal = LOW IF COUNT OK SI LEVELh 70dB ST signal = LOW RDS DATA OK FM RDS OK or NG OK or NG OK or NG OK or NG OK or NG AM (M

12、W, LW) OK or NG OK or NG NG IC251 NG, RV251 adjustments FE101, IC251 NG, or IF count buffer amp (Q251, Q401) NG IC221 NG, RV221 adjustments IC301 NG, RV301 adjustments IC801 NG DISPLAY NOTE : The preset data will be erased when this test mode is used. Therefore, take down the data before setting thi

13、s mode and preset the data again after completing operations in this mode. 2. Display Tube Check and KEY Check mode 1.Turn OFF the power. 2.While pressing 1 and AUTO-BETICAL SELECT together, turn ON U . 3.While continuously pressing 1 and AUTO-BETICAL SELECT together, check the following. Indication

14、 test pattern * The indication test pattern from 2 to 5 are indicated on only even grids. The display changes every 1 sec. 4.Release 1 and AUTO-BETICAL SELECT . The KEY CHECK mode will be set. 5.All key numbers will be displayed. Key Number : 27 6.Each time the key is pressed, the key number will be

15、 counted down. Each key will be counted only once, at the first time. 7.When all keys have been pressed, the process will end. Microcomputer version indication (1 sec)All light up “7F”Dot area only “60”Dot area only “7E” Dot area only “3D”Dot area only “5F” 1 7F2 603 7E4 3D5 5F RadioFans.CN 收音机爱 好者资

16、料库 4 3. Entering the Factory Preset (In case perform just to write memory of the Factory Preset.) NOTE : As contents of the Factory Preset will be written into memory after completing this check mode, delete contents of memory according to 4. Forced RESET. 1.Turn OFF the power. 2.While pressing 3 an

17、d AUTO-BETICAL SELECT together, turn ON U . 4. Forced RESET (Used to delete the contents of Factory Preset when it is written into the preset memory.) Clears all the RAMs and sets the initial state 1.Turn OFF the power. 2.While pressing 5 and AUTO-BETICAL SELECT together, turn ON U . 3.When “All cle

18、ar” is indicated on the display tube, it means that “Forced Reset” has been completed. 5 SECTION 3 ELECTRICAL ADJUSTMENTS Precautions in Repairing If the front end unit fails, it is difficult to repair the inner circuits, so replace the entire front end unit. Set “IF : WIDE” after the all adjustment

19、s. Standard Setting of FM Stereo RF Signal Generator. How to switch IF BAND : WIDE/NARROW and ANT ATT : ON/OFF Method 1: 1.Set the reception mode to FM. 2.Push the MENU button and turn the TUNING/SELECT to indicate “Reception” on the fluorecent display tube, then press the ENTER button. 3.Rotate the

20、 TUNING/SELECT knob in the clokwise direction. (Proceeds onto the step 5 when rotated in the counterclokwise direction.) 4.Turn the TUNING/SELECT knob to indicate “ANT ATT : OFF” on the fluorescent display tube, then press the ENTERl button. 5.Turn the TUNING/SELECT knob to indicate “IF : NARROW” or

21、 “IF : WIDE” on the fluorescent display tube, then press the lENTER button. When the IF BAND : NARROW is set, “NARROW” is indicated on the fluorescent display tube. 6.Set WIDE after the operation. * When set to standby for inputs using the TUNING/SELECTl knob, “SELECT” is indicated on the fluorecent

22、 display tube. Method 2: After the test modes “2. Display Tube Check and KEY Check mode” or “3. Entering the Factory Preset”, “IF : NARROW” and “IF : WIDE” are switched every time pressing RETURN button the IF BAND : NARROW is set “NARROW” is indicated on the fluorescent display tube. Likewise, the

23、mode can be switched between “ANT ATT : ON” and “ANT ATT : OFF”. When set to ANT ATT : ON, the fluorescent display tube indicates ANT ATT. FM SECTION0dB = 1V set FM RF SSG 1kHz highpass filter distortion meter FM ANTENNA (75)LINE OUT STEREO STANDARD SIGNAL MONAURAL STANDARD SIGNAL Carrier frequency

24、: 98MHz Modulation : Audio 1kHz Main channel (L+R) : 33.75kHz deviation Sub channel (LR): 33.75kHz deviation Pilot: 7.5kHz Deviation Carrier frequency : 98MHz Modulation : Audio 1kHz 75kHz deviation FM Discriminator ADJUSTMENT (NULL and MONO Distortion Adjustment) Setting: IF BAND : WIDE ANT ATT : O

25、FF Procedure: 1.Tune the set to 98 MHz. 2.Adjust IFT252 for 0V reading on the digital voltmeter. . NULL 3.Adjust IFT253 for a minimum reading on the distortion meter. . MONO Distortion (THD) 4.Repeat the adjustments of 2 and 3 several times. Note : When replacing the ceramic filter, perform this ali

26、gnment. set FM RF SSG 1kHz highpass filter distortion meter FM ANTENNA (75) Modulation : Monaural Standard signal Output level : 6mV (76dB) (at 75 open) LINE OUT Digital Voltmeter (DC range) TP251 NULL terminal 6 Stereo Level Adjustment Setting: IF BAND : WIDE ANT ATT : OFF Procedure: 1.Tune the set

27、 to 98 MHz. 2.Adjust RV251 to the point (moment) when the “STEREO” indicator will change from going off to going on. Narrow Gain Adjustment Setting: IF BAND : NARROW ANT ATT : OFF Procedure: 1.Tune the set to 98 MHz. 2.Set “IF BAND : NARROW” according to the procedure of “How to switch IF BAND WIDE/

28、NARROW” on page 6. 3.Adjust RV231 to the point (moment) when the “STEREO” indicator will change from going off to going on. FM Meter Level Adjustment Setting: IF BAND : WIDE ANT ATT : OFF Procedure: 1.Tune the set to 98 MHz. 2.Press DISPLAY button to display the digital signal, then adjust RV221 to

29、be display as “SIG 70dB”. set FM RF SSG FM ANTENNA (75) Modulation : Stereo Standard signal Output level : 18V (25dB) (at 75 open) set FM RF SSG FM ANTENNA (75) Modulation : Stereo Standard signal Output level : 18V (25dB) (at 75 open) set FM RF SSG FM ANTENNA (75) Modulation : Stereo Standard signa

30、l Output level : 3mV (76dB) (at 75 open) Stereo Separation Adjustment Setting: IF BAND : WIDE Procedure: 1.Refer to “How to switch IF BAND WIDE/NARROW” on page 6. L-CH Stereo separation : A B R-CH Stereo separation : C D The separations of both channels should be equal. set FM RF SSG FM ANTENNA (75)

31、LINE OUT level meter Modulation : Stereo Standard signal Output level : 6mV (76dB) (at 75 open) FM stereo Signal generator Output channel L-CH R-CH R-CH L-CH Level meter connection L-CH L-CH R-CH R-CH Level meter reading (dB) A B Adjust RV301 for minimum reading on Level meter C D Adjust RV301 for m

32、inimum reading on Level meter ST-SB920 7 8 Waveforms U : B+ Line. V : B Line. Voltages and waveforms are dc with respect to ground under no-signal (detuned) conditions. no mark : FM ( ) : MW : LW : Impossible to measure Voltages are taken with a VOM (Input impedance 10 M). Voltage variations may be

33、noted due to normal production tol- erances. Waveforms are taken with a oscilloscope. Voltage variations may be noted due to normal production tol- erances. Circled numbers refer to waveforms. Signal path. F: FM f: AM For printed wiring boards. Note: X : parts extracted from the component side. b :

34、Pattern from the side which enables seeing. Note: The components identified by mark ! or dotted line with mark ! are critical for safety. Replace only with part number specified. Indication of transistor C These are omitted EB IC701 ! X2 2 5.2 Vp-p 4.19MHz 4.332MHz IC801 ! OSC1 1 3.6 Vp-p AM SECTION

35、 AM Meter Level Adjustment Setting: BAND : LW Procedure: 1.Set AM RF signal generator so that the AM antenna input level becomes 74dB/m. 2.Adjust RV402 so that 1 to 10 indication bars light up on the signal meter. Adjustment Location TUNER BOARD Component Side AM RF SSG loop antenna set loop antenna

36、 (Supplied accessories) 60 cm AM antenna terminal (TM1) 30% amplitude modulation by 400 Hz signal Carrier frequency : 216kHz Modulation : AUDIO 400Hz, 30% modulation Field strength dB (V/m) =SSG output level dB (V/m) 26 dB. FE101 RV402 AM Meter Level RV251 Stereo Level RV221 FM Meter Level RV231 Nar

37、row Gain IFT252 (NULL) TP251 (NULL) RV301 Stereo Separation IFT253 (THD) IFT252, 253 FM Discriminator CNP702 18 THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS. (In addition to this, the necessary note is printed in each block.) For schematic diagrams. Note: All capacitors are i

38、n F unless otherwise noted. pF: F 50 WV or less are not indicated except for electrolytics and tantalums. All resistors are in and 1/4 W or less unless otherwise speci- fied. : internal component. C : panel designation SECTION 4 DIAGRAMS 4-1. CIRCUIT BOARDS LOCATION POWER SW board TRANS board TUNER

39、board DISPLAY board ENCODER board ST-SB920 9 10 4-2. SCHEMATIC DIAGRAM DISPLAY SECTION See page 8 for Waveforms. See page 19 for IC Pin Function. ST-SB920 11 12 4-3. PRINTED WIRING BOARD DISPLAY SECTION See page 8 for Circuit Boards Location. DISPLAY BOARD TRANS BOARD POWER SW BOARD ENCODER BOARD B

40、TUNER BOARD CNP701 A TUNER BOARD CNP702 C TUNER BOARD CNP952 1-668-809- 11 (11) 1-668-810- 11 (11) 1-669-149- 1-668-809- 11 (11) 11 (11) AC IN SHIFT DISPLAYPTYTAMEMORYBANDON/OFFANTENNAFM MODECHARACTERMENUENTERRETURN DIRECT TUNING/SELECT TUNING MODE NEWS /INFO AUTO-BETICAL SELECT 098762 3451 16 S901

41、1 2 CN951 1 2 1 2 ECP900 1 5 123 1 18 9 1 1 100 3 3031 50 51 8081 FL701 FLUORESCENT INDICATOR TUBE 12 A B C D E F G 34567891011121314 Semiconductor Location Ref. No.Location D701C-13 D702B-13 D703B-13 D705C-13 D707D-13 IC701B-9 IC702B-11 Q701C-13 ST-SB920 13 14 4-4. PRINTED WIRING BOARD TUNER SECTIO

42、N See page 8 for Circuit Boards Location. B DISPLAY BOARD CN701 C TRANS BOARD CN952 A DISPLAY BOARD CN702 1-668-808- 11 (11) TUNER BOARD LINE OUT CNP702CNP701 CNP952 81 1 1 5 8 916 18 E 1 2 3 EE E E NULL NULL STEREO LEVEL FM METER LEVEL AM METER LEVEL NARROW GAIN STEREO SEPARATION EON CONTROL OUT 18

43、 916 E EE EE E E EEEE E 18 916 16 17 20 10 16 19 E 1110 120 E E E E FE101 FM FRONT END E E E E E 17 1 1 1 22 11 12 4 58 2 3 RL CNJ301 ANTENNA FM 750 COAXIAL AB TM401 FE401 AM FRONT END IFT 252 IFT252 THD IFT253 IFT 253 12 A B C D E F G H I 345678910111213 Semiconductor Location Ref. No. Location D22

44、1H-3 D251H-9 D301C-11 D371B-12 D401C-4 D402E-4 D901C-8 D902C-8 D903C-7 D904C-7 D905D-7 D906H-12 D907D-7 D908C-8 IC221H-2 IC251H-7 IC301D-11 IC302C-10 IC401D-5 IC801G-11 IC901D-8 Q200G-3 Q201H-4 Q202H-4 Q204H-4 Q205H-5 Q231G-5 Q232G-5 Q233G-4 Q234H-6 Q235G-6 Q236G-6 Q237G-6 Q251H-9 Q301B-10 Q302B-9 Q

45、303B-8 Q304B-8 Q401E-6 Q402C-5 Q403C-5 Q404D-5 Q405C-5 Q521E-8 Q522E-8 Q523E-8 Q801E-11 Q901D-7 ST-SB920 15 16 4-5. SCHEMATIC DIAGRAM TUNER SECTION (1/2) See page 20 for IC Block Diagrams. ST-SB920 17 18 4-6. SCHEMATIC DIAGRAM TUNER SECTION (2/2) See page 8 for Waveforms. See page 20 for IC Block Di

46、agrams. BUFFER 19 4-7. IC PIN FUNCTION (DISPLAY BOARD) IC701 System Control (PD780205GF-040-3BA) Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 to 46 47 to 78 79 80 to 84 85 to 100 Pin Name VDD ANT ATT BAND1 BAND2 IF-B NC MON

47、O TUN RESET X2 X1 GND NC LOCK VDD CLK DATA D-IN CE BLN ST CAL AST AVSS MUTE EON PGM DATA RDS R2 KEY 2 KEY 1 SI AVDD AVREF RIN R1 RDS CLK POWER GND IS 1 to 5 P1 to P32 V LOAD P33 to P37 G1 to G16 I/O I O I I O O I O I I O O I O I I I I I I I I I O O O Function Power supply (+5V). Not used. (Open) Not

48、 used. (Open) Not used. (Open) Not used. (Open) Not used. (Open) Not used. (Open) Not used. (Open) Not used. (Open) System reset input. Oscillation signal output (4.19MHz). Oscillation signal input (4.19MHz). Ground. Not used. (Open) Lock signal input. Power supply (+5V). PLL clock to FE101. PLL dat

49、a to FE101. PLL data from FE101. PLL Latch to FE101. Not used. (Open) Stereo display detection. Not used. (Open) Auto stop signal detection. Ground.(Analog) Muting signal output. External control. Not used. (Open) RDS data input. Rotary encoder phase detection. Key input. Key input. Signal input. Analog power supply (+5V). Reference voltage (+5V). Remote control input. Rotary encoder number of rotation