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NAD T744 Service Manual

Other manuals for T744: Owner's Manual

Summary of T744

  • Page 1

    Nad service manual t 74 4 t 744 a/v receiver a/v receiver draft date: 08 ma y 2007.

  • Page 2: Safety Information

    2 safety information.

  • Page 3: Service Safety Precautions

    3 service safety precautions 1. Replacing the fuses caution: for continued protection against the risk of fire replace only with same type of fuse. Reference designator database part number description f751*ah 20-001-0075-90 fuse time-lag 7a 250v 5 x 20mm sic ul/csa (rohs) f752*ah 20-001-0076-90 fus...

  • Page 4: Specifications

    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 sensitivity (ref. 8 ohms, 1 khz) 260 ±±±±± 20mv s/n ratio (a-wtd, 1khz, 1 w, 8 ohm, sl/sr/bl) ≥≥≥≥≥ - 7...

  • Page 5

    5 dts section output level (vol 0 db) : fl/fr/c/sl/sr track 6 1 khz 2.5 ±±±±± 0.2 w channel difference (fl ref) : fl/fr/c/sl/sr track 6 1 khz ±±±±± 1.0 db harmonic distortion (audio filter) : fl/fr/c/sl/sr track 10-14 1 khz ≤≤≤≤≤ 0.08 % frequency response (20 hz to 20 khz) track 26-30 +2/-1.5 subwoo...

  • Page 6

    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 audio 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...

  • Page 7: Disassembly Instructions

    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 i...

  • Page 8: Wiring Diagram

    8 wiring diagram tuner j705a j705b from transformer 32 28 30 29 6 8 31 33 26 27 25 25 24 9 10 12 23 21 20 19 18 17 16 15 14 13 7 4 5 3 2 1 11 22 for t2743 120v ver. For t2743 120v ver. J203a j713b j714b j753b j204b j713a j714a j782b j715a j720a j709a j502b j704a j707a j710a j717a j719a j711a j715b j...

  • Page 9: Wiring Diagram Parts List

    9 wiring diagram parts list item database part number description remark 1 17-012-2959-90 cable assy 3 ways awg=18 3.96p ul1007 amp1 l=180mm bd-j504a 2 17-012-2969-90 cable assy 5 ways p3.96 awg18 ul1007 amp1 l=200mm bd-j501a 3 17-012-2976-90 cable assy 12 ways awg=26 2.5p ul2877 amp1 l=120mm bd-j50...

  • Page 10

    10 item database part number description remark 29 17-010-0033-90 ffc cable 17 pins p1.25 l=200mm j720c w/ shield 30 17-010-0069-90 ffc cable 20 pins p1.25 l=120mm j604c w/ shield 31 17-010-0035-90 ffc cable 20 pins p1.25 l=200mm j713c w/ shield 32 17-010-0036-90 ffc cable 28 pin p1.25 l=160mm j602c...

  • Page 11: Block Diagram

    11 block diagram.

  • Page 12: Special Function

    12 special function feature keys press on front panel reset for ah version video 6 + source up reset for c version video 6 + source down ntsc / pal selection video 6 + memory vfd all display video 6 + tone defeat am freq. Step am/fm + fm mute version check video 6 + tone control details & waveforms ...

  • Page 13: Amplifier Adjustment

    13 r522 r545 r571 p501 p801 p802 r835 r836 p502 p503 amplifier adjustment idle current 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 ...

  • Page 14: Pcb Layout

    14 pcb layout audio board power supply (standby) / power switch.

  • Page 15

    15 composite video board - component side composite video board - copper side.

  • Page 16

    16 component video board - component side component video board - copper side digital board - component side digital board - copper side.

  • Page 17

    17 dsp board - copper side dsp board - component side.

  • Page 18

    18 front / center amplifier board.

  • Page 19

    19 surround amplifier board.

  • Page 20

    20 keyboard - component side - copper side.

  • Page 21

    21 main board.

  • Page 22

    22 multi-channel board - component side - copper side.

  • Page 23

    23 pre-out board - component side - copper side.

  • Page 24

    24 speaker terminal board trigger board video 6 board power supply (secondary) led board.

  • Page 25

    25 s-video board - component side s-video board - copper side.

  • Page 26: Schematic Diagram

    26 schematic diagram audio switch resistors : unless otherwise specified are carbon film. Note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All ceramic cap acitors, unless other wise specified, are 50v , 10%..

  • Page 27

    27 component video resistors : unless otherwise specified are carbon film. Note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All ceramic cap acit ors, unless other wise specified, are 50v , 10%..

  • Page 28

    28 e c b 2sa2878 e c b 2sa933 dtc123esa e c b composite video resistors : unless otherwise specified are carbon film. Note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All ceramic cap acitors, unless other wise specified, are 50v , 10%..

  • Page 29

    29 power supply (secondary) note: 1 . R e sistors, unless otherwise specified, are 1/6w, 5%. 2. Components marked are safety critial p arts..

  • Page 30

    30 power supply (stand by) e c b 2sc1815 resistors : f-fusible, unless otherwise specified are carbon film. Note: 1 . R e s is t o rs, unless otherwise specified, are 1/6w, 5%. 2. Components marked are safety critial p arts..

  • Page 31

    31 dtc123esa e c b trigger resistors : unless otherwise specified are carbon film. Note: 1 . R e s is t o r s , u n l e s s o therwise specified, are 1/6w, 5%. 2. All ceramic cap acit ors, unless other wise specified, are 50v , 10%..

  • Page 32

    32 video 6 resistors : unless otherwise specified are carbon film. Note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All ceramic cap acit ors, unless other wise specified, are 50v , 10%..

  • Page 33

    33 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 cap acit ors, unless other wise specified, are 50v , 10%..

  • Page 34

    34 e c b 2sa1016 2sc2362 b c e 2sa1606 2sc4159 b c e 2sa2031 2sc5669 e c b 2sb772 e c b 2sd600 dtc123esa e c b front / center amplifier note: 1. Resistors, unless other wise specified, are 1/6w , 5%. 2. All ceramic cap acit ors, unless other wise specified, are 50v , 10%. 3. Components marked are sa...

  • Page 35

    35 surround amplifier e c b 2sc2362 b c e 2sa1606 2sc4159 b c e 2sa2031 2sc5669 e c b 2sd600k 2sd631k dtc123esa e c b e c b 2sa1016k 2sc2362 resistors : rn-ceramic case, mo-metal oxide, unless otherwise specified are carbon film. Note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All c...

  • Page 36

    36 speaker a & b rs-232.

  • Page 37

    37 digital in & out.

  • Page 38

    38 e b c 2sd600k main board note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All ceramic capacitors, unless otherwise specified, are 50v, 10%..

  • Page 39

    39 pre-out note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All ceramic capacitors, unless otherwise specified, are 50v, 10%..

  • Page 40

    40 e c b 2sc1815 dsp note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All ceramic capacitors, unless otherwise specified, are 50v, 10%..

  • Page 41

    41 e c b 2sc1815 e c b 2sc1015 keyboard note: 1. Resistors, unless otherwise specified, are 1/6w, 5%. 2. All ceramic capacitors, unless otherwise specified, are 50v, 5%..

  • Page 42

    42 e c b 2sc2878 e b c ss8050 ss8550 dta114esa dtc114esa e c b multi-ch 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%..

  • Page 43: Ic Block Diagram

    43 1 2 3 4 5 6 7 8 9 10 dir a1 a2 a3 a4 a5 a6 a7 a8 gnd 20 19 18 17 16 15 14 13 12 11 vcc g b1 b2 b3 b4 b5 b6 b7 b8 (1) (2) (3) (4) (5) (6) (7) (8) (9) (11) (19) (18) (17) (16) (15) (14) (13) (12) oe ck d0 1d c1 en d1 d2 d3 d4 d5 d6 d7 q0 q1 q2 q3 q4 q5 q6 q7 74lvq574 dsp board: u1008, u1009 w27c020...

  • Page 44

    44 74hcu04 digital board: u1201 & u1202 component video: u4304 1a 1y 2a 2y 3a 3y gnd 1 2 3 4 5 6 7 14 13 12 11 10 9 8 6a v cc 6y 5a 5y 4a 4y cs49326 dsp board: u1001 74hc157 dsp board: u1004 1 15 select strobe 2 1a 1b 4 1y 3 5 2a 2b 7 2y 6 11 3a 3b 9 3y 10 14 4a 4b 12 4y 13 74hc157 dsp board: u1004.

  • Page 45

    45 tcm810 keyboard: u214 at24c16 keyboard: u210 sda vss scl wc vcc / e2 m24cxx 1 2 3 4 8 7 6 5 / e2 / e2 / e2 nc / e1 / e1 / e1 / nc nc / e0 / e0 / nc / nc nc /1kb /2kb /4kb /8kb 16kb vcc reset**(reset) gnd tcm809 xenb tcm810 xenb 1 2 3 *3-p in sot-23b note: *3-pin sot-23b is equivalent to jedec to-...

  • Page 46

    46 hcf4094b keyboard: u204~u207 serial in clock strobe latch 1 3-state 1 output enable 2 serial out q' s 10 serial out q s 9 15 1 d q cl cl 3 cl cl 1 cl cl 2 d q cl cl latch 2 tr tr latch 3 tr tr 3- state 2 3- state 3 3 d q cl cl q stages 3 - 7 2 2 2 2 2 2 2 2 q3 q2 q1 vss vdd q7 q8 q6 q5 q4 cl cl c...

  • Page 47

    47 timer 0 int ram 256x8 t0 t1 rxd txd wr rd ea psen ale/ xtal2 xtal1 euart cpu timer 1 int1 ctrl int0 (3) (3) c51 core (3) (3) (3) (3) port 0 p0 port 1 port 2 port 3 parallel i/o ports & ext. Bus p1 p2 p3 xram 1kx8 ib-bus pca reset prog watch dog pca eci vss v cc (3) (3) (1) (1) timer2 t2ex t2 (1) ...

  • Page 48

    48 0 2 com "y" out/in 3 1 inh v ee gnd 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 v cc 2 1 com "x" out/in 0 3 a b y channels in/out x channels in/out x channels in/out y channels in/out 74hc4052 74hc4052 component video board: u4302 & u4303 74hc00 component video board: u4304 1a 1b 1y 2a 2b 2y gnd 1 2 3...

  • Page 49

    49 m61516fp multi-channel board: u601.

  • Page 50: Exploded View

    50 exploded view 1 2 3 4 5 78 77 6 8 7 9 10 11 12 13 14 15 16 17 18 18 18 19 19 20 20 21 22 22 22 22 22 20 27 22 23 23 58 22 23 23 24 24 25 26 28 29 30 31 32 33 35 34 22 36 37 38 39 33 75 41 42 43 44 46 47 48 49 50 51 52 53 54 55 56 57 59 60 61 62 63 64 71 65 73 74 67 68 69 70 72 66 40 76 23 23 45.

  • Page 51: Exploded View Parts List

    51 exploded view parts list item database part number description qty 1 08-002-0042-00 fan dc 80 x 80 x 25 12v 0.15a 2700rpm df128025bb w/360mm 1 2 10-005-0187-90 xformer pw ei-96 115v/230v t744 t96-0313002-21 issue 6 1 3 11-001-0061-90 power switch tv-8 10a/250vac ul/csa/vde/f/d/s ps3- 22spa-p7cz b...

  • Page 52

    52 item database part number description qty 53 21-001-0025-90 volume knob assy (d. Grey) [for grey ver.] 1 21-001-0026-90 volume knob assy (titanium) [for titanium ver.] 1 54 23-237-0020-90 fascia t744 (grey) r.1 [for grey ver.] 1 23-237-0020-92 fascia t744 (graphite) r.2 [for grey ver.] 1 23-237-0...

  • Page 53

    53 item database part number description qty 73 21-002-0154-90 power button bezel (grey) r.1 [for grey ver.] 1 21-002-0154-92 power button bezel (graphite) r.2 [for grey ver.] 1 21-002-0163-90 power button bezel (painted titanium) r.1 [for titanium ver.] 1 21-002-0163-92 power button bezel (new tita...

  • Page 54: Electrical Parts List

    54 electrical parts list reference no. Database part no. Description power amp module 50-940-0744-90 t744 power amp module front & center amp board pcb assembly 27-909-0744-90 t744ah (us) front and center amp board regulator u501 01-004-0049-00 ic volt reg 12v 1a to-220 njm7812 isowatt resistors r52...

  • Page 55

    55 reference no. Database part no. Description thermistor m504 20-004-0039-00 thermistor ptc 100 ohm pth9mo4bh471ts2f333 thermal protector m505 20-004-0043-90 thermal cut off switch 90c st-22 diodes d501-d503,d505-d507,d509-d511, d521,d524-d528, d531-d536 04-001-0001-00 diode sw 4ns do35 1n4148 d529...

  • Page 56

    56 reference no. Database part no. Description diodes d522,d523,d801-d806,d809,d821- d824 04-001-0001-00 diode sw 4ns do35 1n4148 audio board pcb assembly 27-919-0744-90 t744ah (us) audio board assembly capacitors c317-c319,c320-c329,c331 03-002-0129-00 cap elec ss 10uf 16v 20% 85c rad height =7mm m...

  • Page 57

    57 reference no. Database part no. Description slide switch s1 11-002-0042-90 sw slide 2p2t right l=9 rca jacks j1001,j1002,j1003,j1004 15-003-0021-90 rca jack 1 black pcb mount gold smd ics u1203 01-012-0061-00 ic logic 8-channel multiplexer sop u1201,u1202 01-012-0066-00 ic logic hex inverter smd ...

  • Page 58

    58 reference no. Database part no. Description u1021 01-027-0002-90 ic 24bit 96khz surround sound code ssop cs4228aks u1005 01-027-0003-90 ic 96khz digital audio interface receiver smd cs8415a-csz smd resistors r1151 02-007-0042-00 res smd 1k ohm 5% 1/16w 0603 r1090,r1091 02-007-0135-00 res smd 2.7k...

  • Page 59

    59 reference no. Database part no. Description key board and led board pcb assembly 50-951-0744-90 t744 keyboard and led assembly key board pcb assembly 27-922-0744-90 t744ah (us) keyboard board assembly capacitors c212 03-002-0135-00 cap elec gs 1000uf 10v 20% 85c rad st5 c255,c258 03-002-0137-00 c...

  • Page 60

    60 reference no. Database part no. Description smd resistors r234 02-007-0042-00 res smd 1k ohm 5% 1/16w 0603 r208 02-007-0089-00 res smd 0 ohm +/-5% 1/10w 0805 r216 02-007-0094-00 res smd 1k ohm 1% 1/4w 1206 r238 02-007-0132-00 res smd 12k ohm 5% 1/16w 0603 r220,r256-r259,r261,r263- 02-007-0139-00 ...

  • Page 61

    61 reference no. Database part no. Description diodes d701-d710 04-001-0003-00 diode rect 1a/1000v do41 win4007 reel d715 04-005-0020-90 diode bri 4a/70v rs402l d711 04-002-0045-90 diode zener bzx55 30v 1/2w 5% do35 bzx55- transistors q701 05-001-0065-00 xtr pw npn 1a/100v to-126 2sd600ke regulators...

  • Page 62

    62 reference no. Database part no. Description diodes d602,d604 04-002-0047-90 diode zener bzx55 7.5v 1/2w 5% do35 bzx55- c7.5v pre-out board pcb assembly 27-924-0744-90 t744ah (us) pre-out board assembly capacitors c624-c625,c640, c645,c650,c655, c670, c675,c693-c698 03-002-0073-00 cap elec gs 22uf...

  • Page 63

    63 reference no. Database part no. Description smd capacitors c747-c758 03-009-0075-00 cap cer smd 0.1uf 50v 20% y5v 0603 tape smd diodes d615-d638 04-007-0039-90 diode zener smd 12v 500mw 5% sod123 power supply board pcb assembly*ah, 27-903-0744-90 pcb assy t744ah (us) power supply board pcb assemb...

  • Page 64

    64 reference no. Database part no. Description secondary board pcb assembly 27-926-0744-90 pcb assy t744ah (us) normal secondary board resistors r781-r785 02-010-0011-00 res mo 0.22 ohm 5% 1/2w capacitors c790,c791 03-002-0149-00 cap elec lp 8200uf 63v 20% 85c rad c781-c785,c787-c788 03-004-0031-00 ...

  • Page 65

    65 reference no. Database part no. Description c4146,c4136 03-004-0049-00 cap mpf 0.47uf 63v +/-5% dmf 5 series c4175 03-004-0117-00 cap mpf 0.047uf 100v +/-5% mem c4138 03-011-0001-00 cap trimmer 20pf 20% sealed hori. Pitch=5mm cvn620 transistors q4132 05-001-0072-00 transistor ss npn hef 100 200mh...

  • Page 66

    66 reference no. Database part no. Description phone jacks m351,m352,m353,m354,m355,m357 15-002-0028-90 phone jack 1 black pcb mount 3.5mm right diodes d351-d353 04-002-0040-00 diode zener bzx79 5.1v 1/2w 5% do35 bzx79-c 5.1v video -6 board pcb assembly 27-931-0744-90 t744ah (us) video-6 board assem...

  • Page 67: Packing Diagram & Parts List

    67 packing diagram & parts list 6 5 4 1 2 3 5 9 7 8 item database part no. Description qty. 1 24-003-0122-90 polybag manual 1 2 25-027-0001-90 fm wire antenna l=2700mm 1 w/y-terminals (rohs) 2 25-027-0002-90 am loop antena w/stand 1 2 15-015-0001-90 300 to 75 ohm antenna adapter 1 2 24-004-1934-90 t...