Akai-ACM480L-cs-sm 电路图 维修手册.pdf

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1、A K A I SERuiCE mimuni MIDI COMPONENT STEREO SYSTEM MODELzyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA AC-M480L RadioFans.CN 收音机爱 好者资料库 ABBREVIATIONS FOR SERVICE MANUAL (CASSETTE) Abbrevialion Explanation Abbrevialion Explanation A C Alternating Currenl MIN MINute A / D Analog/Digital MML Max

2、imum Modulation Level A F Auto Fader MOL Maximum Output Level AMP AMPlifier MPX Muiti PleX AR Anti Recording NC Not Connecled (No Conneclion) A T BIAS Auto Tuning BIAS NFB Negative Feed Back A T T ATTenuator NORM NORMal B A L BALance NR Noise Reduciion B E F Band Elimination Filter OSC OSCillator (O

3、SCillation) BSS Blank Search System P Pulse C A P M CAPsTan Motor PB Play Back CH CHannel QMSS Quick Memory Search System COMP COM Parator QR Quick Reverse CONT CONTinuance R CH Right CHannel C R L P Computer Recording Level Process- ing R F C RECord (RECording) CS Chip Select REV RE Verse D/A Digit

4、al/Analog ROT ROTation DC Direct Current REW REWind D E T DETector SEC SECond DISCRI DiSCRIminator S E L E SELEctor DUB DUBbing SENS SENSiiivity EQ EQualizer SEPP Single Ended Push Pull FF(orFFWD) Fast Forward SIG SIGnal F L D FLuorescent Display SPECT SPECTrum FREQ FREQuency STD STanDard F W D ForW

5、arD sw switch GND GrouND SYSCON SYStem CONtroI H High T P Test Point HPF High Pass Filter T R I G TRIGa IND INDicator V C A Voltage Control Attenuator IPLS Inslant Program Location System VOL VOLume L Low V O L T VOLTage L C H Left CHannel VR Variable Resistor L E D Light Emitining Diode X T A L cys

6、TAL MEMO MEMOry X I Normal speed MICOM MIcroCOMputer X2 Dubble speed RadioFans.CN 收音机爱 好者资料库 ABBREVIATIONS (TUNER) Abbreviation Explanation Abbreviation Explanation AFC Auto Frequency Control MEMO MEMOry AGC Auto Gain Control MICOM MIcro-COMputer ALC Auto Level Control MIN MINimum AM Amplitude Modul

7、ation MIX MlXing AMP AMPlifier MPX Multi PleX ANT ANTenna MW Medium Wave (frequency) BAT T BATTe r y NC No Connection BLK BLocK NEB Negative Feed Back BUFF BLiFFer OSC OSCillator COMP COMParator PCB Printed Circuit Board DET DF-TecttDETctor) PLL Phase Locked Loop FLD Q.D Quadrature Detector FM Frequ

8、ency Modulation Rch Right channel FREQ FREQuency REF REFerence GND (IrouND REG REGulator H HiRh RF Radio Frequency HPF HiKh Pass Filter SEG SEGment IF Intermediate Frequency SELE SELEctor IHF Institut of lKh Fidelily SENS SENSitivity INl) INDicator SIG SIGnal I/ O In/ Out S/ N Signal to Noise Ratio

9、JW Jumper Wire SSG Standard Signal Generator L Lovv STD STanDard LCD Liquid Cr ystal Display SW sw it ch : Short Wave (frequency) Lch Left channel THD Total Harmonie Distortion LEI) Light Emitining Diode TP Test Point LP F Low Pass Filter VCO Voltage Controlled Oscillator LW Long Wave (Frequency) VR

10、 Variable Resistor XT A L Crystal RadioFans.CN 收音机爱 好者资料库 SAFETY INSTRUCTIONS PRECAUTIONS DURING SERVICING 1. Parts identified by the A (*) symbol are critical for safety. Replace only with parts number specified. 2. In addition to safety, other parts and assembhes are spe- cified for conformance wi

11、th such regulations as those ap- plying to spurious radiation. These must aiso be replaced only with specified replace- ments. Examples: R F converters, tuner units, antenna selector switches, R F cables, noise blocking capacitors, noise blocking filters, etc. 3. Use specified interna! wiring. Note

12、especially: 1) Wires covered with P V C tubing 2) Doubl insulated wires 3) High voltage leads 4. Use specified insulating materiais for hazardous live parts. Note especially: 1) Insulation Tape 2) P V C tubing 3) Spacers (Insulating Barriers) 4) Insulation sheets for transistors 5) Plastic screws fo

13、r fixing microswitch (especially in turntable) 5. When replacing A C primary side components (trans- formers, power cords, noise blocking capacitors, etc), wrap ends of wires securely about the terminals before soldering. 7. Check that replaced wires do not contact sharp edged or pointed parts. 8. A

14、lso check areas surrounding repaired locations. 9. Use care that foreign objects (screws, solder dropiets, etc.) do not remain inside the set. SAFETY CHECK AFTER SERVICING After servicing, make measurements of leakage-current or resistance in order to determine that exposed parts are ac- ceptably in

15、sulated from the supply circuit. The leakage-current measurement should be done between accessible metal parts (such as chassis, ground terminal, microphone jacks, signal-input/output connectors, etc.) and the earth ground through a resister of 1500 ohms paral- leled with a 0.15 fiF capacitor, under

16、 the units normal working conditions. The leakage-current should be less than 0.5 mA rms A C . The resistance measurement should be done between ac- cessible exposed metal parts and power cord plug prongs with the power switch (if included) ON. The resistance should be more than 2.2 Mohms. PRECAUTIO

17、NS FOR LITHIUM BATTERY The lithium battery explode when heated excessively. O B S E R V E T H E F O L L O W I N G W H E N R E P L A C I N G Replace with the same make and type only Use soldering iron in recommended way only. Place battery in correct polarity. Do not short the terminals. Do not recha

18、rge battery. Do not dispose of battery in fire. 6. Observe that wires do not contact heat producing parts (heatsinks, oxide metal film resistors, fusible resistors, etc). DANGERI IRECOMMENDED WAY INFORMATION SYMBOLS FOR PRIMARY DESTINATION Alphabet indicates the destination of the units as listed be

19、low. Symbols Principal Destinations USA U K CS Canada Europe (except UK) m Japan m Australia W. Germany only Universal Area Custom version 2 SERVICE MANUAL SPECIFICATIONS A M P L I F I E R S E C T I O N Power output By D1N(1 kHz 8 ohms) . 42 W+42 W Music power I 90 W Power band width 10 Hz60 kHz/.5%

20、 S/N ( I H F - A ) P H O N O M M 72 dB T U N E R etc 90 dB Channcl separation 53 dB Damping factor 30 Required speaker impedance 8-16 ohms Input sensitivity/impedance P H O N O M M 4.5 mV/47 kohms C D / V C R 300 mV/47 kohms Frequency response P H O N O 0.5 dB T U N E R etc 5 Hz50 kHz (-3 dB) Graphe

21、c equaUzer 5 band Center frequency 63 Hz. 250Hz. 1 kHz,4kHz. 16kHz Adjust range 8 dB F M S E C T I O N Tuning frequency range . 87.5 MHz-108.0 MHz Usable sensitivity l2.7dBf Quieting sensitivity (S/N=50dB) 19.2 dBf (Mono)/40.2 dBf (Stereo) Capture radio 2.0 dB Selectivity (400 kHz) 60 dB Image rejce

22、tion ratio 50 dB IF rejection ratio 50 dB Suprious rejection ratio . 80 dB A M suppression 50 dB Sub carrier suppression ratio 55 dB S/N 70dB(Mono)/60dB(Stereo) T.H.D 0.2 %(Mono)/0.4 /(Stereo) Stereo separation (1 kHz) 40 dB Frequency response 30 Hz - 1 5 kHz + 1.0 dB AM S E C T I O N MW band Tuning

23、 frequency range . 531-1602 kHz Usable sensitivity (Loop antenna) 300jiV Selectivity 25 dB Image rejection ratio 40 dB IF rejection ratio 45 dB S/N 40 dB T.H.D 1.0% L W band Tuning frequency range . 144-351 kHz Usable sensitivity (Loop antenna) SOOfiV Selectivity 30 dB Image rejection ratio 40 dB IF

24、 rejection ratio 45 dB S/N 35 dB T.H.D 2,0% D E C K S E C T I O N Heads T A P E 1 H D head for playback X 1 T A P E I I recording/playback X I Erase head X 1 Motors T A P E I D C Motor X 1 T A P E I I D C Motor X I Frequency response Normal 30 Hz - 14 k H z + 3 dB S/N 56 dB T.H.D 0.8 % Power require

25、ments 220 V , 50 Hz for Europe except U K 240 V, 50 Hz for U K Dimensions 350(V) X 268(H) X 370 (D)mm Weights 7.7 kg Standard accessories Remo-con transmitter X I Batteries for remocon X2 F M antenna X I F M antenna Plug X I A M loop antenna X I Operators manual X I * For improvement purposes, speci

26、fications and design are subject to change without notice. * Noise reduction manufactured under license from dolby laboratories licensing corporation. DOLBY and CE symbol are trade marks of dolby licensing corporation. SERVICE MANUAL 3 I. C O N T R O L S 1-1. F R O N T P A N E L Qzyxwvutsrqponmlkjih

27、gfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA REMOTE SENSOR Window Q Tuning Display O POWER Sv/itch O INPUT S E L E C T O R Buttons and Indicators I SURROUND ON (.M.)/OFF ( Switch- 0 PHONES Jack PLAYBACK Deck I Cassette Lid and Helder -O P R E S E T STATION MEMORY Button I P R E S E T STATION Selector Buttons (

28、1 to m I PLAYBACK Deck I Operation Selector Buttons VI4-1-4 O BAND Selector Button O FM AUTO/MONO Selector Button O TUNING DOWN/UP Control Volume Indicator VOLUME Control ( BALANCE Control - 5 BAND GRAPHIC EQUALIZER Controls RECord Indicator - DUBBING S P E E D ( X 2zyxwvutsrqponmlkjihgfedcbaZYXWVUT

29、SRQPONMLKJIHGFEDCBA J L X X1) Switch - DOLBY NR ON ( ) / O F F (X) Switch I R E C / P L A Y B A C K Deck II Operation Selector Buttons R E C / P L A Y B A C K Deck II Cassette Lid and Holder O POWER Switch Depress to turn the System on. O Tuning Display Shows the tuning information. O REMOTE SENSOR

30、Window Receives signals of the WIRELESS REMOTE CONTROL UNIT to control the Deck Receiver. O P R E S E T STATION MEMORY Button Used to enter a preset station. e P R E S E T STATION Selector Buttons (1 to 16) Used to enter preset stations and tune in entered stations. O BAND Selector Button Depress to

31、 select the MW.LW or F M band. O FM AUTO/MONO Selector Button Depress to select the FM AUTO or MONO mode. O TUNING DOWN/UP Control Depress to tune in a station manually. O INPUT SELECTOR Buttons and Indicators TAPE, TUNER (SCAN), PHONO and CD/VCR Depress to select an audio source you want to listen

32、to. SURROUND ON (.M.) / O F F ( X ) Switch Depress tor the surround effect (for use with optional Surround Speakers, Model AE-S91). PHONES Jack A pair of stereo headphones (8 ohms) can be connected here for private listening. 5 BAND GRAPHIC EQUALIZER Controls 63, 250, IK, 4K and 16K Used to finely a

33、djust the frequency levels between 63 Hz and 16 kHz during playback and recording operations (except tape dubbing.) Fig. 1-1 Controls on the F R O N T P A N E L (El BALANCE Control Used to adjust the left and right channel balance. VOLUME Control Used to adjust the volume level. Can be moved using t

34、he WIRELESS REMOTE CONTROL UNIT. Volume Indicator Shows the audio volume level. Goes off for a few seconds when the POWER Switch is turned on or any INPUT SELECTOR Button is pressed. Also, turned off by the WIRELESS REMOTE CONTROL UNIT MUTE Button, with sound muted. R E C (record) Indicator Shows th

35、at the REC/PLAYBACK Deck II is in the recording mode. DUBBING SPEED (x2 J L X x1) Switch Depress to select the tape dubbing speed. DOLBY NR 0 N ( J L ) / 0 F F ( X ) Switch Depress to turn on or off the Dolby NR system. REC/PLAYBACK Deck II Cassette Lid and Holder Used to load a tape for recording a

36、nd playback in the REC/PLAYBACK Deck II. REC/PLAYBACK Deck II Operation Selector REC, , - / E J E C T and PAUSE Depress to record, play, rewind, fast forward, stop and eject, or pause a tape in Deck II. PLAYBACK Deck I Operation Selector / E J E C T Depress to play, rewind, fast forward, or stop and

37、 eject a tape in Deck I. PLAYBACK Deck I Cassette Lid and Holder Used to load a tape for playback only in the PLAYBACK Deck I. SERVICE MANUAL 4 1-2. REAR PANEL FM ANTENNA Connector- AM ANTENNA Connectors- BEAT C A N C E L Switch Ground ( ) Conneotor PHONO Input Connectors C D / V C R Input Connector

38、s - LINE OUT Connectors _9 rzzr mm Power Cord Front S P E A K E R S Connectors SURROUND S P E A K E R S Connectors Fig. 1-2 Controls on the REAR PANEL 1-3. WIRELESS REMOTE CONTROL UNIT ) Backward PROGRAM Search (M) Button- E ) Forward PROGRAM Searcti (W) Button Program MEMO (memory) Button s FRONT P

39、ANEL BLK FIXATION SCREW VIEW FROM BOTTOM SIDE FRONT PANEL BLK FIXATION SCREW LID SPRING Fig. 4-2 FRONT PANEL BLK FIXATION SCREW Fig. 4-1 1) Be sure that the A C Power Cord is disconnected. 2) Disconnect the connectors ( P I to P5) on the D E C K P C B and remove three D E C K P C B F I X A T I O N S

40、 C R E W S , then remove the D E C K P C B from Front panel B L K . 3) Disconnect the connectors J301 ( B A S E P C B ) and J 2 0 ! ( M A I N V O L U M E P C B ) , then resoid a jumper wire between M A I N V O L U M E P C B and B A S E P C B . 4) Remove P O W E R P C B F I X A T I O N S C R E W S an

41、d pull out the P O W E R P C B to the arrow (A) direction. 5) Remove Seven F R O N T P A N E L B L K F I X A T I O N S C R E W S , then pull out the F R O N T P A N E L B L O C K and remove the R E C L E D P C B from the F R O N T P A N E L B L O C K . 6) Remove the L I D S P R I N G S a n d S C R E

42、 W S t o ( R e f e r to Fig 4-2). Then remove the M E C H A N I C A L B L O C K . V. M E C H A N I C A L A D J U S T M E N T 5-1. W I N D I N G T O R Q U E M E A S U R E M E N T IN E A C H M O D E Set the cassette torque meter (AJ-751179) and measure the torque in each mode. For F A S T F O R W A R

43、D and R E W I N D , measure at the end of tape when tape has stopped running. P L A Y mode Take up torque ; 35 to 75 g-cm Back tcnsion torque : 1 to 6 g-cm F A S T F O R W A R D and R E W I N D mode Take up torque : 60 to 160 g-cm 5-2. H E A D A Z I M U T H A L I G N M E N T A D J U S T M E N T 1) C

44、onnect the A C milli-vohmeter to L I N E O U T of both channels and Connect CH-1 and CH-2 of the oscilloscope to output terminal of both A C milli-voltmeter. 2) Playback a lOkHz, -15vu test tape (AT-750778) and Adjust the H E A D A Z I M U T H A L I G N M E N T S C R E W through the H E A D A Z I M

45、U T H A L I G N M E N T H O L E so that the waveformes on the oscilloscope are in the same phase at the maximum output level. -n-. rrr) TZZI I I tUee AZHUTH (.ISNtCHT Fig. 5-1 Adjustment points of H E A D Azimuth alignment SERVICE MANUAL 7 VI. ELECTR I CAL AD JUS TM EN T 6-1. I N S T R U M E N T C O

46、 N N E C T I O N S O F B A S E P C B A D J U S T M E N T - t : TEST LOOP ANTENNA KEEP THE TEST ANTEN- NA CLOSER TO THE UNIT OISTORTION METER AC VOLTMETER - O INPUT O O O- l OANTENI I T O - - J OUTPUT JJ AC VOLTMETER AC VOLTMETER Fig. 6-1 Instrument Connection of AM Adjustment Fig. 6-2 Instrument Con

47、nection of F M Adjustment 6-2. H O W T O C A L L T H E P R E S E T F R E Q U E N C Y F O R T H E A D J U S T M E N T Short circuit momentarily tvvo P R E S E T jumper wires as shown Fig 6-3. Then select required frequency by pushing one of the P R E S E T station button on the F R O N T P A N E L ac

48、cording to chart 6-1. CONTROL PCB ifTl I I I RESET I 1 REMOT CONTROL V RECEIVER View from Pottern side. LCD 7 Fig. 6-3 The internal frequency preset memory is set as below. PRESET STATION C H l F M 88.00 MHz CH2 F M 90.00 MHz C H 3 F M 98.00 MHz C H 4 F M 100.00 MHz C H S F M 106.00 MHz CH6 F M 108.00 MHz CH7 L W 160 kHz C H S L W 300 kHz C H 9 F M 95.75 MHz C H I O MW 603 kHz C H l l MW 999 kHz CH12 MW 1404 kHz CH13 MW 801 kHz CH14 MW 1305 kHz CH15 L W 200 kHz CH16 L W 350 kHz Chart 6-1 SERVICE MANUAL 8 6-