NAD-T743-avr-sm 电路图维修手册.pdf

上传人：cc518

文档编号：260626

上传时间：2025-10-13

格式：PDF

页数：65

大小：9.68MB

《NAD-T743-avr-sm 电路图维修手册.pdf》由会员分享，可在线阅读，更多相关《NAD-T743-avr-sm 电路图维修手册.pdf（65页珍藏版）》请在收音机爱好者资料库上搜索。

1、NAD SERVICE MANUALT 743 T 743 A/V Receiver A/V Receiver DRAFT DATE: 12 MAR 2004RadioFans.CN 收音机爱好者资料库 2 SAFETY INFORMATION RadioFans.CN 收音机爱好者资料库 3 SERVICE SAFETY PRECAUTIONS 1. Replacing the fuses CAUTION: FOR CONTINUED PROTECTION AGAINST THE RISK OF FIRE REPLACE ONLY WITH SAME TYPE OF FUSE. Refe

2、rence DesignatorPart NumberDescription F751*AH 33-0101001-00-48FUSE 7A 250V TIME-LAG5 X 20mm SIC UL/CSA F751*C 33-0141002-00-48FUSE 4A 250V TIME-LAG 5 X 20mm VDE/UL TSD F752*AH 33-0111006-00-48FUSE 1.6A 250V TIME LAG LBC 5x20mm TSD UL/CSA/VDE/SEMKO F752*C 33-0151006-00-48FUSE 800mA 250V TIME LAG LBC

3、 5x20mm TSD UL/CSA/VDE/SEMKO FH751-FH752 33-1000000-00-88FUSE CLIP 0.05mm FC-53-11 NOTE: : USA, CANADIAN MODEL ONLY. : EUROPEAN MODEL ONLY. 2. Safety check out (Only U.S.A. model) Before returning the product to the customer, make leakage current or resistance measurements to determine that exposed

4、parts are acceptably insulated from supply circuit. CONTENTS DESCRIPTIONPAGE SPECIFICATIONS. 4 - 5 REAR PANEL / FRONT PANEL VIEW . 6 DISASSEMBLY INSTRUCTIONS . 7 WIRING DIAGRAM. 8 BLOCK DIAGRAM. 9 SPECIAL FUNCTION . 10 DETAILS & WAVEFORMS ON SYSTEM & TEST & DEBUGGING . 10 ADJUSTMENT POINTS DIAGRAM /

5、 AMPLIFIER ADJUSTMENT .11 PCB LAYOUT . 12 - 23 SCHEMATIC DIAGRAM . 24 - 40 IC BLOCK DIAGRAM . 41 - 46 EXPLODED VIEW. 47 EXPLODED VIEW PARTS LIST. 48 - 49 ELECTRICAL PARTS LIST . 50 - 62 PACKING DIAGRAM . 63 VERSION HISTORY . 64 Parts marked with the symbol are critical with regard to the risk of fir

6、e and electric shock. Replace only with parts recommended by the manufacturer. RadioFans.CN 收音机爱好者资料库 4 SPECIFICATIONS POWER AMPLIFIER SECTION Rated distortion(Rated power level into 8 ohms, THD 20 Hz-20 kHz FL/C/FR) 0.1 % (Rated power level into 8 ohms, THD 20 Hz-20 kHz SL/SR/BS) 0.1 % Input Sensi

7、tivity(ref. 8 ohms, 1 kHz)150 20 mV S/N Ratio(A-wtd, 1kHz, 1 W, 8 ohm, SL/SR/BL) - 72 dB Frequency Response(20 Hz - 20 kHz)0 1.0 dB Channel Balance(1 dB to -40 dB, 1 kHz) 2 dB (-41 dB to -50 dB, 1 kHz) 3 dB Audio muting at 1 kHz 55 dB Subwoofer out, 500 mV in (THD at 2 V O/P, 100 Hz) 0.5 % Crosstalk

8、(500 mV input, 10 W, 1 kHz) -57 dB Controls Bass(at 500 mV in, 1 W out, 100 Hz) 10 dB 2 dB Treble(at 500 mV in, 1 W out, 10 kHz) 10 dB 2 dB DOLBY DIGITAL SECTION Channel Difference(FL ref. Track 30) 1.2 dB Frequency Resporse at Dolby config.2SL Track 46 200 - 20 kHz 0.8 dB SR Track 47 200 - 20 kHz 0

9、.8 dB C Track 44 200 - 20 kHz 0.8 dB Harmonic Distortion(1 W, Audio LPF, Dolby Congfig 1)FL Track 65 997 Hz 0.08 % FR Track 67 997 Hz 0.08 % SL Track 68 997 Hz 0.08 % SR Track 69 997 Hz 0.08 % C Track 66 997 Hz 0.08 % S/N Ratio(TRACK 30 for O/P 1 W, FAUSE)CCIR / ARM 65 dB Audio LPF 70 dB A-WTD 70 dB

10、 Channel Separation(1 W, A-WTD FILTER)Track 65 997 Hz 60 dB DOLBY PRO LOGIC II SECTION Frequency Resporse I/P mode : L, R: 1 V in, 1 W, Ch L/R40 Hz0 2.0 dB 20 kHz0 2.0 dB I/P mode : L=R: 1 V in, 1 W, Ch /L/R40 Hz0 2.0 dB Ch C20 kHz0 2.0 dB I/P mode : L=-R: 1 V in, 1 W, Ch SL/SR40 Hz0 2.0 dB 20 kHz0

11、2.0 dB S/N Ratio (200 mV in, 1 W, A-WTD w/ 1 k termination) I/P mode : L, R: 1 kHz, Ch L/R 65 dB I/P mode : L=R: 1 kHz, Ch C 65 dB I/P mode : L=-R: 1 kHz, Ch SL/SR 65 dB THD (2.2 V in, 1 W, w/ 80 kHz LPF, 1 kHz) 0.2 % Power output Surround Mode 5 x 50W (16.98 dBW) 5 DTS SECTION Output Level (Vol 0 d

12、B): FL/FR/C/SL/SRTrack 61 kHz0.9 1.3 W Channel Difference (FL ref): FL/FR/C/SL/SRTrack 61 kHz 1.0 dB Harmonic Distortion (Audio Filter) : FL/FR/C/SL/SRTrack 10-14 1 kHz 0.08 % Frequency Response (20 Hz to 20 kHz)Track 26-30+2/-1.5 Subwoofer Output Level1 kHz ref at pre-out (FL)Play Track 10, charge

13、to 1512.5 2 dB AM TUNER SECTION Input level is expressed as the reading in open circuit of 75-ohm source impedance signal generator Usable sensitivity(999/1000 kHz) 30 dBuV S/N Ratio(5 mV in) 38 dB THD(5 mV in) 3 % IF Rejection(450 kHz) 36 dB Image Rejection(F+2xIF) 28 dB Selectivity 17 dB Output170

14、 20 mV Loop sensitivity(20 dB S/N) 999/1000 kHz 66 dB 603/600 kHz 66 dB 1404/1400 kHz 66 dB Frequency Response(100 - 2.3 kHz, 5 mV) 6 dB FM TUNER SECTION*C*AH Input level is expressed as the reading in open circuit of 75-ohm source impedance signal generator Usable sensitivity(98 MHz) 15 dBV 15 dBuv

15、 S/N Ratio(60 dB, IHF wtd)Mono 63 dB 63 dB Stereo 63 dB 63 dB Frequency Response(20 Hz - 15 kHz, 60 dB)0 1.5 dB0 1.5 dB Channel Separation(60 dB)100 Hz 30 dB 30 dB 1 k 38 dB 38 dB 10 kHz 30 dB 30 dB Alternate Channel Selectivity (40 dB, 400 kHz) 60 dB 45 dB Capture Ratio(40 dB) 3 dB 3 dB AM Suppress

16、ion (60 dB, 100% Mod. FM, 30% Mod. AM) 48 dB 48 dB Image Rejection(119.4 MHz) 65 dB I.F. Rejection(10.7 MHz) 78 dB Pilot Suppression(98 MHz) 60 dB 60 dB THD (60 dB, L=R 75 kHz for AH, 40 kHz Dev for C)Mono 0.25 % 0.25 % Stereo 0.35 % 0.35 % Auto-Search SensitivityOn 24 dB 24 dB Off 15 dB 15 dB RDS d

17、ecode Sensitivity 26 dB PHYSICAL SPECIFICATIONS Dimensions (Width x Height x Depth)435 x 167 x 382 mm Net Weight18.50 Kg (40.70 lbs) Shipping Weight22.20 Kg (48.84 lbs) 6 FRONT PANEL REAR PANEL / FRONT PANEL VIEW REAR PANEL 1.FM & AM ANTENNA 2.MONITOR OUT 3.CD INPUT 4.DIGITAL AUDIO INPUT & DIGITAL A

18、UDIO OUTPUT 5.SOFT CLIPPING ON/OFF 6.IR INPUT & OUTPUT 7.+12V TRIGGER INPUT & OUTPUT 8.COMPONENT VIDEO IN & COMPONENT VIDEO OUT 9.AC POWER CORD 10.POWER SWITCH 11.SWITCHED AC OUTLETS 12.SPEAKERS A & B 13.DVD, SAT, VCR, VIDEO 4 & VIDEO 5 14.MAIN IN / AUDIO PRE-OUTS / SUBWOOFER OUT 15.TAPE INPUT & OUT

19、PUT 16.DISC INPUT 17.5.1 CH. INPUTS 1.STANDBY SWITCH 2.STANDBY LED 3.AM / FM 4.DISPLAY 5.MEMORY 6.FM MUTE / MODE 7.PRESET DOWN / UP 8.SEARCH DOWN / UP 9.VFL DISPLAY 10.VOLUME (SETUP) 11.SOURCE DOWN / UP 12.SURROUND MODE 13.LEVELS 14.TONE DEFEAT 15.TONE CONTROLS 16.SPEAKERS A & B 17.VIDEO 6 INPUT 18.

20、PHONES 7 DISASSEMBLY INSTRUCTIONS 1.Remove machine screws M4.0 x 8.0 (1 to 6) from the side panels. Remove tapping screw 3.0 x 8.0 (7 to 10) from the back panel. Refer to Figure No. 1. 2.Pull both sides of the TOP COVER slightly outwards 11 and tilt approx. 35 and then remove in the direction as ind

21、icated by the arrow 12. Refer to Figure No. 2. Figure No. 1 Figure No. 2 8 MAIN BOARD SPEAKER BOARD TRIGGER BOARD SECONDARY BOARD S-VIDEO BOARD AUDIO BOARD COMPONENT VIDEO BOARD DIGITAL BOARD VIDEO BOARD POWER SUPPLY BOARD #1 MULTI-CHANNEL PRE-OUT BOARD AMP. BOARD #2AMP. BOARD #1 TUNER J705B T743 WI

22、RE DIAGRAM DATE : 10/03/04 REV. A FROM TRANSFORMER 82-0526135-01-XX CABLE ASSY 5 WAYS #26 UL2468 L=150MM 82-0826135-00-XX CABLE ASSY 8 WAYS #26 UL2877 L=480MM 82-0826135-04-XX CABLE ASSY 82-0426135-05-XX CABLE ASSY 4 WAYS #26 UL2468 L=400MM 82-0318235-03-XX CABLE ASSY 3 WAYS #18 3.96P UL1007 L=180MM

23、 82-0518238-01-XX CABLE ASSY 5 WAYS #18 3.96P 82-1224135-02-XX CABLE ASSY 12 WAYS #26 2.5P UL2877 L=120MM 82-0326135-03-XX CABLE ASSY 3 WAYS #26 2.5P UL2854 L=150MM 82-0426135-02-XX CABLE ASSY 4 WAYS #26 2.5P UL2877 L=500MM 82-0226135-04-XX CABLE ASSY 2 WAYS #26 2.5P UL1533 L=540MM 82-0426135-00-XX

24、CABLE ASSY 4 WAYS #26 UL2877 L=200MM 36-2028121-71-XX FFC CABLE 20 PINS P1.25 L=120MM 36-1728201-71-XX FFC CABLE 17 PINS P1.25 L=200MM 82-0326135-06-XX CABLE ASSY 3 WAYS #26 2.5P UL2854 L=250MM 36-2028201-71-XX FFC CABLE 20 PINS P1.25 L=200MM FFC CABLE 28 PINS P1.25 L=200MM 82-0318235-03-XX CABLE AS

25、SY 3 WAYS #18 3.96P UL1007 L=180MM 82-0626135-02-XX CABLE ASSY 6 WAYS #26 2.5P UL1533 L=350MM 82-0826135-00-XX CABLE ASSY 8 WAYS #26 2.5P UL2877 L=480MM 82-0626135-03-XX CABLE ASSY 6 WAYS #26 2.5P UL2877 L=480MM 82-1226135-00-XX CABLE ASSY 12 WAYS #26 2.5P UL2877 L=240MM 82-0318235-02-XX CABLE ASSY

26、3 WAYS #18 3.96P UL1007 L=120mm 82-0318235-05-XX CABLE ASSY 3 WAYS #18 3.96P UL1015 L=320mm 36-2828141-71-XX FFC CABLE 28 PIN P1.25 L=140mm 36-2828141-71-XX FFC CABLE 28 PIN P1.25 L=140mm 36-3028061-71-XX FFC CABEL 30 PINS P1.25 L=60mm 82-0326135-02-98 CABLE ASSY 3 WAYS #26 2.5P UL2854 L=700mm 82-14

27、26135-00-98 CABLE ASSY 14 WAYS #26 2.5P UL2877 L=420mm 82-0116438-03-XX CABLE ASSY 1 WAY #16 UL1672 BLUE L=100mm 82-0116436-12-XX CABLE ASSY 1 WAY #16 UL1672 BROWN L=100mm 82-0118435-00-XX CABLE ASSY 1 WAY AWG18 UL1007 BLACK L=100mm W/ RING TERMINAL 82-0118435-01-XX CABLE ASSY 1 WAY #18 UL1007 BLACK

28、 L=360mm W/ RING TERMINAL 82-0518235-03-XX CABLE ASSY 5 WAYS #18 3.96P UL1007 L=300mm CABLE ASSY 5 WAYS #18 3.96P UL1007 L=350mm 82-0118435-00-XX CABLE ASSY 1 WAY #18 UL1007 BLACK L=100mm W/ RING TERMINAL J203A J713B J753BJ204BJ350B J702A J715A J720A J709A J721A J502B J704A J707A0 J710A J717A J719A

29、J711A J715B J604B J203B DSP BOARD J1010B J1009B VIDEO 6 INPUT BOARD LED BOARD J783A J782A J784A J781A J786A J7 J7 J414B J602B J603B J707B J612A J611A J717B J601B J601A J602A J603A J751B J754B J753_N5J753_L J759_L J758_N J504A J612A J502A J503A J501A J505A J506A J781B J501B J506A J503B J611B J801A J2

30、04A B J201 J701 WIRING DIAGRAM 9 BLOCK DIAGRAM Volume Encoder 10 SPECIAL FUNCTION FEATUREKEYS PRESS ON FRONT PANEL RESET FOR AH VERSIONVIDEO 6 + SOURCE UP RESET FOR C VERSIONVIDEO 6 + SOURCE DOWN NTSC / PAL SELECTIONVIDEO 6 + MEMORY VFD ALL DISPLAY VIDEO 6 + TONE DEFEAT AM FREQ. STEPAM/FM + FM MUTE

31、DETAILS & WAVEFORMS ON SYSTEM TEST & DEBUGGING T89C51RD2 (U202) main clock is at 20MHz (X202) T89C51RD2 (U201) main clock is at 20MHz (X201) UPPER - +5V supply to KEYBOARD when power up LOWER - RESET line (TCM810LENB713) when power up UPPER - OUTPUT ENABLE (pin 24) of EPROM (W27C02) when changing SU

32、RROUND MODES LOWER - CHIP ENABLE (pin 22) of EPROM (W27C02) when changing SURROUND MODES SCLK (pin 43 of CS49326) LRCLK (pin 42 of CS49326) MCLK (pin 30 of CS49326) NOTE: The waveforms are based on software version V1.27. 11 R522R545R571 P501 P801 P802 R835R836 P502P503 AMPLIFIER ADJUSTMENT Idle Cur

33、rent 1.Rotate R522 fully clockwise. 2.Connect DC millivoltmeter to P501 (i.e. Across half of R523, 0.22 Ohm resistor). 3.Turn on the unit. 4.Adjust R522 for 1mV reading on voltmeter. 5.Leave power on for at least 5 min, and check for idle current again. 6.Repeat for other channels. CHANNELJUMPERVR F

34、LP501R522 FRP502R545 CP503R571 SLP801R835 SRP802R836 ISC Sensitivity 1.Connect 8 ohm loading to all channels. 2.Rotate R881 fully clockwise. 3.Load all channels at full power using 1kHz sine wave. 4.At this time, monitor the THD of the SL,SR output. Clipping should occur before full power achieved.

35、5.The procedure is finish at this step. 6.Load all channels at full power using 1kHz sine wave with 4 ohm load. 7.The clipping power(at THD 0.1%) should less than 85W. ADJUSTMENT POINT DIAGRAM FRONT/CENTER AMPLIFIER BOARD SURROUND AMPLIFIER BOARD 12 PCB LAYOUT AUDIO BOARD POWER SUPPLY (STANDBY) / PO

36、WER SWITCH 13 COMPOSITE VIDEO BOARD - COMPONENT SIDE COMPOSITE VIDEO BOARD - COPPER SIDE 14 COMPONENT VIDEO BOARD - COMPONENT SIDE COMPONENT VIDEO BOARD - COPPER SIDE DIGITAL BOARD - COMPONENT SIDE DIGITAL BOARD - COPPER SIDE 15 DSP BOARD - COPPER SIDE DSP BOARD - COMPONENT SIDE 16 FRONT / CENTER AM

37、PLIFIER BOARD 17 SURROUND AMPLIFIER BOARD 18 KEYBOARD - COMPONENT SIDE- COPPER SIDE 19 MAIN BOARD 20 MULTI-CHANNEL BOARD - COMPONENT SIDE- COPPER SIDE 21 PRE-OUT BOARD - COPPER SIDE PRE-OUT BOARD - COMPONENT SIDE - COPPER SIDE 22 SPEAKER TERMINAL BOARD TRIGGER BOARD VIDEO 6 BOARD POWER SUPPLY (SECON

38、DARY) LED BOARD 23 S-VIDEO BOARD - COMPONENT SIDE S-VIDEO BOARD - COPPER SIDE 24 SCHEMATIC DIAGRAM AUDIO SWITCH RESISTORS : UNLESS OTHERWISE SPECIFIED ARE CARBON FILM. NOTE: 1. RESISTORS, UNLESS OTHERWISE SPECIFIED, ARE 1/6W, 5%. 2. ALL CERAMIC CAPACITORS, UNLESS OTHERWISE SPECIFIED, ARE 50V, 10%. 2

39、5 COMPONENT VIDEO RESISTORS : UNLESS OTHERWISE SPECIFIED ARE CARBON FILM. NOTE: 1. RESISTORS, UNLESS OTHERWISE SPECIFIED, ARE 1/6W, 5%. 2. ALL CERAMIC CAPACITORS, UNLESS OTHERWISE SPECIFIED, ARE 50V, 10%. 26 E C B 2SA2878 E C B 2SA933 DTC123ESA E C B COMPOSITE VIDEO RESISTORS : UNLESS OTHERWISE SPEC

40、IFIED ARE CARBON FILM. NOTE: 1. RESISTORS, UNLESS OTHERWISE SPECIFIED, ARE 1/6W, 5%. 2. ALL CERAMIC CAPACITORS, UNLESS OTHERWISE SPECIFIED, ARE 50V, 10%. 27 POWER SUPPLY (SECONDARY) NOTE:1. RESISTORS, UNLESS OTHERWISE SPECIFIED, ARE 1/6W, 5%. 2. COMPONENTS MARKED “” ARE SAFETY CRITIAL PARTS. 28 POWE

41、R SUPPLY (STAND BY) E C B 2SC1815 RESISTORS : F-FUSIBLE, UNLESS OTHERWISE SPECIFIED ARE CARBON FILM. NOTE:1. RESISTORS, UNLESS OTHERWISE SPECIFIED, ARE 1/6W, 5%. 2. COMPONENTS MARKED “” ARE SAFETY CRITIAL PARTS. 29 DTC123ESA E C B TRIGGER RESISTORS : UNLESS OTHERWISE SPECIFIED ARE CARBON FILM. NOTE:

42、1. RESISTORS, UNLESS OTHERWISE SPECIFIED, ARE 1/6W, 5%. 2. ALL CERAMIC CAPACITORS, UNLESS OTHERWISE SPECIFIED, ARE 50V, 10%. 30 VIDEO 6 RESISTORS : UNLESS OTHERWISE SPECIFIED ARE CARBON FILM. NOTE: 1. RESISTORS, UNLESS OTHERWISE SPECIFIED, ARE 1/6W, 5%. 2. ALL CERAMIC CAPACITORS, UNLESS OTHERWISE SP

43、ECIFIED, ARE 50V, 10%. 31 E C B 2SA933 E C B 2SC1740 E C B 2SC1815 2SC2878 DTC144ESA DTC123ESA E C B S-VIDEO RESISTORS : UNLESS OTHERWISE SPECIFIED ARE CARBON FILM. NOTE: 1. RESISTORS, UNLESS OTHERWISE SPECIFIED, ARE 1/6W, 5%. 2. ALL CERAMIC CAPACITORS, UNLESS OTHERWISE SPECIFIED, ARE 50V, 10%. 32 E C B 2SA1016 2SC2362 B C E 2SA1606 2SC4159 B C