Nad T-775 Service Manual

NAD

SERVICE MANUAL

T 775

Surround Sound Receiver

T 775

Surround Sound

Receiver

SAFETY INFORMATION

Manufactured under license under U.S. Patent #’s: 5,451,942; 5,956,674; 5,974,380; 5,978,762; 6,226,616; 6,487,535; 7,003,467; 7,212,872 & other U.S. and worldwide patents issued & pending. DTS is a registered trademark & the DTS logos and Symbol are trademarks of DTS, Inc. © 1996-2007 DTS, Inc. All Rights Reserved.

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

F8001*AH 20-001-0078-90 FUSE TIME-LAG 10A/250VAC 5X20mm UL/CSA 5T F8001*C,CT

5X20mm TSD UL/CSA/VDE/CCC WALTER

F8002*AH 5x20mm TSD UL/CSA/VDE/SEMKO

F8002*C,CT TSD UL/CSA/VDE/CCC WALTER 5X20mm VDE/UL/CSA 5T

NOTE:

<*AH > : USA, CANADIAN MODEL ONLY. <*C, *CT > : 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 parts are acceptably insulated from supply circuit.

20-001-0072-90 FUSE TIME-LAG 6.3A 250VAC

20-001-0076-90 FUSE 1.6A 250V TIME LAG LBC

20-001-0069-90 FUSE TIME-LAG 800mA 250V 5x20mm

Parts marked with the symbol are critical with regard to the risk of ﬁre and electric shock.

CONTENTS

DESCRIPTION PAGE

SPECIFICATIONS ..............................................................................................................................4 - 5

REAR PANEL / FRONT PANEL VIEW ...................................................................................................6

DISASSEMBLY INSTRUCTIONS ...........................................................................................................7

WIRING DIAGRAM ............................................................................................................................8 - 9

BLOCK DIAGRAM.................................................................................................................................10

SPECIAL FUNCTION ..........................................................................................................................11

DETAILS & WAVEFORMS ON SYSTEM & TEST & DEBUGGING................................................12-15

ADJUSTMENT POINTS DIAGRAM / AMPLIFIER ADJUSTMENT .......................................................16

PCB LAYOUT ..................................................................................................................................17- 40

SCHEMATIC DIAGRAM ...................................................................................................................41-67

ELECTRICAL PARTS LIST ..............................................................................................................68-92

IC BLOCK DIAGRAM .....................................................................................................................93-117

EXPLODED VIEW ........................................................................................................................118-119

EXPLODED VIEW PARTS LIST ..................................................................................................120-123

SINGLE CHANNEL SERVICE KIT ...............................................................................................124-125

PACKING DIAGRAM ...........................................................................................................................126

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) 1 ± 0.1 V

S/N Ratio (A-wtd, 1kHz, 1 W, 8 ohm, SL/SR/BL) ≥ - 80 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 (500 mV input, 10 W, 1 kHz) ≥ -54 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.2 SL Track 46 200 - 20 kHz ± 0.8 dB SR Track 47 200 - 20 kHz ± 0.8 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 (31 for O/P 1 W, Track 35) CCIR / ARM ≥ 65 dB Audio LPF ≥ 64 dB A-wtd ≥ 68 dB Channel Separation (1 W, 20 kHz LPF) Track 65 997 Hz ≥ 55 dB

DOLBY PRO LOGIC II SECTION

Frequency Response

I/P mode : L, R : 1 V in, 1 W, Ch L/R 40 Hz 0 ± 2.0 dB 20 Hz 0 ± 2.0 dB I/P mode : L=R : 1 V in, 1 W, Ch /L/R 40 Hz 0 ± 2.0 dB Ch C 20 kHz 0 ± 2.0 dB I/P mode : L=-R : 1 V in, 1 W, Ch SL/SR 40 Hz 0 ± 2.0 dB 20 kHz 0 ± 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 ≥ 60 dB I/P mode : L=R : 1 kHz, Ch C ≥ 60 dB I/P mode : L=-R : 1 kHz, Ch SL/SR ≥ 60 dB THD (2.2 V in, 1 W, w/ 80 kHz LPF, 1 kHz) ≤ 0.2 %

DTS SECTION

Output Level (Vol 0 dB) : FL/FR/C/SL/SR Track 6 1 kHz 0.5 -0.2/+0.8 W Channel Difference (FL ref) : FL/FR/C/SL/SR Track 6 1 kHz 0 ± 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 dB Subwoofer Output Level 1 kHz ref at pre-out (FL) Play Track 10, charge to 15 12.5 ± 1.5 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) ≤ 60 dBμV 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 Output 170 -20/+30 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 dBμ ≤ 15 dBμv S/N Ratio (60 dB, IHF wtd) Mono ≥ 60 dB ≥ 60 dB Stereo ≥ 63 dB ≥ 63 dB Frequency Response (20 Hz - 15 kHz, 60 dBμ) 0 ± 1.5 dB 0 ± 1.5 dB Channel Separation (60 dBμ) 100 Hz ≥ 30 dB ≥ 30 dB 1 k ≥ 32 dB ≥ 32 dB 10 kHz ≥ 30 dB ≥ 30 dB Alternate Channel Selectivity (40 dBμ, ± 400 kHz) ≥ 60 dB ≥ 45 dB Capture Ratio (40 dBμ) ≤ 3 dB ≤ 3 dB AM Suppression (60 dBμ, 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) ≥ 50 dB ≥ 50 dB THD (60 dBμ, L=R 75 kHz for AH, 40 kHz Dev for C) Mono ≤ 0.5 % ≤ 0.5 % Stereo ≤ 0.5 % ≤ 0.5 % Auto-Search Sensitivity On ≥ 24 dBμ ≥ 24 dBμ Off ≤ 15 dBμ ≤ 15 dBμ RDS decode Sensitivity ≤ 26 dBμ −

PHYSICAL SPECIFICATIONS

Dimensions (Width x Height x Depth) 435 x 170 x 423 mm Net Weight 20.8 Kg (45.76 lbs) Shipping Weight 25.7 Kg (56.54 lbs)

REAR PANEL / FRONT PANEL VIEW

REAR PANEL

1. DIGITAL AUDIO IN/OUT

2. HDMI

3. COMPONENT IN/OUT

4. MP DOCK

5. AUDIO/VIDEO 3/4 OUT

6. MONITOR(S-VIDEO,VIDEO)

FRONT PANEL

7. AUDIO/VIDEO 1~6 IN

8. 7.1 CH INPUT

9. XM MODULE INPUT(AH) DAB MODULE INOUT(C,CT)

10. RS-232

11. FM,AM ANTENNA INPUT

12. SOFT CLIPPING

13. +12V TRIGGER OUT

14. IR IN/OUT

15. ZONE 2,3,4

16. AUDIO PREOUT

17. SPEAKERS A, SPEAKER B

18. AC POWER INLET

19. SWITCHED AC OUTLET

20. POWER

1. POWER BUTTON

2. STANDBY LED

3. INFO

4. AM/FM/DB

5. TUNER MODE

6. MEMORY

7. NAVIGATION AND ENTER BUTTON

8. VACUUM, FLUORES CENT DISPLAY(VFD)

9. VOLUME

10. SPEAKER A/B

11. SOURCE

12. LISTENING MODE

13. TONE CONTROLS

14. TONE DEFEAT

15. FRONT INPUT/MP

16. PHONES

17. FRONT INPUT JACKS

18. MP/MIC INPUT

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.

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Figure No. 1

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2. Pull both sides of the TOP COVER slightly outwards 11 and tilt approx. 35 ° and then remove in the direction as indicated by the arrow 12. Refer to Figure No. 2.

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Figure No. 2

WIRING DIAGRAM

WIRING DIAGRAM PARTS LIST

Item Database Part Number Description Remark

1 17-012-2965-90 CABLE ASSY 4 WAYS #26 2.5P L=400mm PSU BD-J8002A

2 17-012-3943-90 CABLE ASSY 1 WAY #16 UL1672 BLUE PSU L=140mm FASTON 4.8mm BD-J8011 3 17-012-3944-90 CABLE ASSY 1 WAY #16 UL1672 BROWN PSU

L=140mm FASTON 4.8mm BD-J8012 4 17-012-3940-90 CABLE ASSY 3 WAYS #26 2.5P UL2854 VOL

L=110 BD-J6004A/B 5 17-012-3938-90 CABLE ASSY 1 WAY #18 UL1007 L=320MM DSP

W/ HEADER BD-J1002A 6 17-012-3378-90 CABLE ASSY 20 WAYS #28 UL2651 L=240mm KEYBOARD

PCB MOUNT -J2002B 7 17-012-3173-90 CABLE ASSY 14 WAYS #26 2.5P UL1533 PRE-OUT

L=100 BD-J5404B 8 17-012-3176-90 CABLE ASSY 3 WAYS #18 3.96P UL1007 SEC

L=80 BD-J5804B 9 17-012-3208-90 CABLE ASSY 4 WAYS #18 3.96p UL1007 SEC BD L=150 J8101A,J8102A 10 17-012-3209-90 CABLE ASSY 4 WAYS #18 3.96P UL1007 SEC BD-

L=170 J8103A+J8104A 11 17-012-3174-90 CABLE ASSY 5 WAYS #18 3.96P UL1007 SPK BD-

L=300mm (W/R/B/V/O) J5403B1-B5 12 17-012-3947-90 CABLE ASSY 4 WAYS #18 3.96P UL1007 L=260 SPK BD-

(W/R/Y/BL) J5802B1-B4 13 17-012-3329-90 CABLE ASSY 3 WAYS #18 UL1007 3.96P L=420 SPK BD-

J8106B1-B3 14 17-012-3330-90 CABLE ASSY 4 WAYS #18 UL1007 3.96P L=440 SPK BD-

J8105B1-B4 15 17-012-3171-90 CABLE ASSY 6 WAYS #26 2.5P UL1533 L=200 V6 VD-

J2006B 16 17-012-3404-90 CABLE ASSY 6 WAYS #26 2.5P UL1007 L=150 V6 BD-

J2005B 17 17-012-3939-90 CABLE ASSY 3 WAYS #26 2.5P UL2468 L=180 ISC BD-

J5803B,J5810B 18 17-012-3930-90 CABLE ASSY 4 WAYS #26 2.5P UL1533 L=160 V6 BD-

J2008A 19 17-012-3936-90 CABLE ASSY 3 WAYS #26 2.5P UL2854 L=310 CONN#1-

J9006A 20 17-012-3937-90 CABLE ASSY 5 WAYS #26 2.5P UL2854/1533 CONN#1-

L=230/320 J9004A/J9005A 21 17-012-3938-90 CABLE ASSY 1 WAY #18 UL1007 L=320 CONN#1-

W/ HEADER JP9001A 22 17-012-3941-90 CABLE ASSY 3 WAYS #26 2.5P UL2854 L=130 CONN#1-

J9008A/B 23 17-012-3457-90 CABLE ASSY 8 WAYS #26 UL1007 2.5P L=120 CONN#2-

J8202B 24 17-012-3458-90 CABLE ASSY 10 WAYS #26 UL1007 2.5P L=80 CONN#2-

J8201B 25 17-010-0122-90 FFC CABLE 17 PINS P1.25 L=360 15 & 16 TUNER-

PINS VOID J5404B 26 17-012-2874-90 CABLE ASSY 1 WAY #16 UL1672 BLUE J8015,J8017

L=100mm 27 17-012-2875-90 CABLE ASSY 1 WAY #16 UL 1015 CHASSIS GND,

GREEN/YELLOW L=100 28 17-012-3166-90 CABLE ASSY 20 WAYS #28 UL2651 L=100mm J2001C,J7001C 29 17-012-3298-90 CABLE ASSY 3 WAYS #18 UL1007 L=420mm J5402A/B 30 17-012-3346-90 CABLE ASSY 26 WAYS #28 UL2651 L=330mm J2301C 31 17-012-3942-90 CABLE ASSY 26 WAYS #28 UL2651 L=230mm J2007C 32 17-012-3948-90 CABLE ASSY 1 WAY #16 UL1672 BROWN L=100 J8013,J8016 33 17-012-3963-90 CABLE ASSY 1 WAY #18 UL1007 L=200 W/ HEADER TUNER J6102A 34 17-012-3965-90 CABLE ASSY 3 WAYS #26 2.5P UL2547 L=500 TUNER J9501A 35 17-012-2924-90 CABLE ASSY 1 WAY AWG18 UL1015 BLACK L=260mm W/RING TERMINAL SEC BD-J8153A-GND

AC OUTLET GND

MAIN-JP7006B-GND,

BLOCK DIAGRAM

SPECIAL FUNCTION

Function Keys Notes

Factory Reset AH Source Down + Front/MP Factory Reset C Source UP + Front/MP Toggle IR Channel Source Down + Power Only for v1.08 or higher. Check MCU Version Source Down + Source UP For v1.03 or higher, this checks all versions. Check DSP Version Source Down + Listening Mode Only for v1.02 or older. Check Current Video Mode Source Down + Tone Controls MIC Test Source Down + Tone Defeat VFD Test Source Down + Display PAL/NTSC Source Down + Memory DAB/XM Source Down + Tuner Band Must cycle power before change takes effect. 9k/10k Source UP + Tuner Band Must reselect AM before change takes effect. XM 1kHz Test Tone Tuner Band + Tuner Mode XM must be selected ﬁrst. XM Signal Strength Tuner Mode for 0.5 seconds XM must be selected ﬁrst. XM Diagnostics Mode Tuner Mode for 3 seconds XM must be selected ﬁrst. Check DAB Module Version Tuner Mode for 3 seconds DAB must be selected ﬁrst. Enter Diagnostics Mode Source Down + Enter Diagnostic Mode Down Source Down + Cursor Right Diagnostic Mode Up Source Down + Cursor Left Power Off All Zones Power Toggle or Power Off for 3 seconds

DETAILS & WAVEFORMS ON SYSTEM TEST & DEBUGGING

DSP

U1007 Pin 17 - X1001C output, 24.576MHz

U1007 Pin 2 - Master clock (Analog), 12.288MHz U1007 Pin 2 - Master clock (PCM), 11.2896MHz

U1007 Pin 70 - Clock for external memory,

100MHz

U1007 Pin 12 – Left/Right clock (Analog), 48kHz U1007 Pin 12 - Left/Right clock (PCM), 44.1kHz

U1007 Pin 9 - Serial clock (Analog), 3.072MHz

MCU

U2001 Pin 12 - X2001A output, 20.000MHz

HDMI

U12 Pin 38 – U3 output, 28.636MHz

U9 Pin 1 –DAC_HS (OSD Off), 31.48kHz U9 Pin 54 –DAC_VS (OSD On, NTSC), 60Hz

U9 Pin 1 –DAC_HS (OSD On), 15.72kHz U9 Pin 54 –DAC_VS (OSD On, PAL), 50Hz

U9 Pin 54 –DAC_VS (OSD Off), 60Hz U9 Pin 4 –DAC_FLD (OSD Off), Idle

U9 Pin 4 –DAC_FLD (OSD On, NTSC), 30Hz U9 Pin 51 –PCLK (OSD On), 27MHz

U9 Pin 51 –PCLK (OSD Off), 27MHz

U9 Pin 4 –DAC_FLD (OSD On, PAL), 25Hz

ADJUSTMENT POINT DIAGRAM

LEFT/RIGHT CHANNEL AMPLIFIER BOARD

SECONDARY / ISC BOARD

AMPLIFIER ADJUSTMENT

Idle Current

1. Rotate R5221 fully clockwise.

2. Connect DC millivoltmeter to P5501 (i.e. Across half of R5228 and R5530, 0.22 Ohm resistor).

3. Turn on the unit.

4. Adjust R5221 for 2mV +/- 0.2mV reading on voltmeter.

5. Leave power on for at least 5 min, and check for idle current again.

6. Repeat for other channels.

CHANNEL JUMPER VR

FL P5501 R5521 FR P5001 R5021 C P5101 R5121 SL P5601 R5621 SR P5201 R5221 BS P5701 R5721 BSR P5301 R5321

ISC Adjustment

A. Rotate R8214 fully clockwise. B. Use 500mV, 1kHZ sine wave, EXT7.1 input, 8ohm loading to all channels. C. Increase the output power of FL/SL/BSL channels to 80W(25.3V). D. Note the THD readings should be larger than 0.2%. E. Rotate R8214 anti-clockwise slowly until the THDreadings is below 0.1%. F. Repeat for R8217 using FR/SR/BSR/C channels.