Nad T-754 Service Manual

DRAFT DATE: 08 MAY 2007

NAD

SERVICE MANUAL

T 754

Surround Sound Receiver

T 754

Surround Sound Receiver

SAFETY INFORMATION

AH VERSION

C VERSION

2

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 20-001-0078-90 FUSE TIME-LAG 10A/250VAC 5X20mm

UL/CSA 5T

F751*C,CT

F752*AH

F752*C,CT

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.

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

5x20mm 5T UL/CSA/VDE/SEMKO

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

5x20mm 5T UL/CSA/VDE/SEMKO

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

5X20mm VDE/UL/CSA 5T

Parts marked with the symbol are critical with regard to the risk of fire and electric
shock. Replace only with parts recommended by the manufacturer.

CONTENTS

DESCRIPTION PAGE

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

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

DISASSEMBL Y INSTRUCTIONS.......................................................................................................... 7

WIRING DIAGRAM......................................................................................................................... 8 - 10

BLOCK DIAGRAM................................................................................................................................11

SPECIAL FUNCTION .......................................................................................................................... 12

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

ADJUSTMENT POINTS DIAGRAM / AMPLIFIER ADJUSTMENT ...................................................... 13

PCB LAYOUT............................................................................................................................... 14 - 29

SCHEMA TIC DIAGRAM ............................................................................................................... 30 - 46

IC BLOCK DIAGRAM ................................................................................................................... 47 - 54

EXPLODED VIEW............................................................................................................................... 55

EXPLODED VIEW PAR TS LIST................................................................................................... 56 - 58

ELECTRICAL P AR TS LIST .......................................................................................................... 59 - 73

PACKING DIAGRAM.......................................................................................................................... 74

3

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) 296

S/N Ratio (A-wtd, 1kHz, 1 W, 8 ohm, SL/SR/BL)

Frequency Response (20 Hz - 20 kHz) 0
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
Subwoofer out, 500 mV in (THD at 2 V O/P, 100 Hz) ≤ 0.5 %
Crosstalk (500 mV input, 10 W, 1 kHz)

±±

± 20 mV

±±

≥≥

≥ - 75 dB

≥≥

±±

± 1.0 dB

±±

≥≥

≥ 55 dB

≥≥

≥≥

≥ -57 dB

≥≥

Controls

Bass (at 500 mV in, 1 W out, 100 Hz)
Treble (at 500 mV in, 1 W out, 10 kHz)

±±

± 10 dB

±±
±±

± 10 dB

±±

DOLBY DIGITAL SECTION

Channel Difference (FL ref. Track 30)
Frequency Resporse at Dolby config.2 SL Track 46 200 - 20 kHz

SR Track 47 200 - 20 kHz
C Track 44 200 - 20 kHz

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

Audio LPF
A-wtd

Channel Separation (1 W, 20 kHz LPF) Track 65 997 Hz

±±

± 1.2 dB

±±
±±

± 0.8 dB

±±
±±

± 0.8 dB

±±
±±

± 0.8 dB

±±

≥≥

≥ 65 dB

≥≥
≥≥

≥ 70 dB

≥≥
≥≥

≥ 70 dB

≥≥
≥≥

≥ 60 dB

≥≥

±±

± 2 dB

±±
±±

± 2 dB

±±

DOLBY PRO LOGIC II SECTION

Frequency Resporse

I/P mode : L, R : 1 V in, 1 W, Ch L/R 40 Hz 0

20 Hz 0

I/P mode : L=R : 1 V in, 1 W, Ch /L/R 40 Hz 0

Ch C 20 kHz 0

I/P mode : L=-R : 1 V in, 1 W, Ch SL/SR 40 Hz 0

20 kHz 0
S/N Ratio (200 mV in, 1 W, A-WTD w/ 1 k termination)
I/P mode : L, R : 1 kHz, Ch L/R
I/P mode : L=R : 1 kHz, Ch C
I/P mode : L=-R : 1 kHz, Ch SL/SR
THD (2.2 V in, 1 W, w/ 80 kHz LPF, 1 kHz) ≤ 0.2 %

4

±±

± 2.0 dB

±±
±±

± 2.0 dB

±±
±±

± 2.0 dB

±±
±±

± 2.0 dB

±±
±±

± 2.0 dB

±±
±±

± 2.0 dB

±±

≥≥

≥ 65 dB

≥≥
≥≥

≥ 65 dB

≥≥
≥≥

≥ 65 dB

≥≥

DTS SECTION

Output Level (Vol 0 dB) : FL/FR/C/SL/SR Track 6 1 kHz 0.3
Channel Difference (FL ref) : FL/FR/C/SL/SR Track 6 1 kHz
Harmonic Distortion (Audio Filter) : FL/FR/C/SL/SR Track 10-14 1 kHz
Frequency Response (20 Hz to 20 kHz) Track 26-30 +2/-1.5
Subwoofer Output Level 1 kHz ref at pre-out (FL) Play Track 10, charge to 15 12.5

±±

± 1.3 W

±±

±±

± 1.0 dB

±±
≤≤

≤ 0.08 %

≤≤

±±

± 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)
S/N Ratio (5 mV in)
THD (5 mV in)
IF Rejection (450 kHz)
Image Rejection (F+2xIF)
Selectivity
Output 170 -20/+30 mV
Loop sensitivity (20 dB S/N)

999/1000 kHz
603/600 kHz
1404/1400 kHz

Frequency Response (100 - 2.3 kHz, 5 mV)

≤≤

≤ 30 dB

≤≤
≥≥

≥ 38 dB

≥≥
≤≤

≤ 3 %

≤≤
≤≤

≤ 36 dB

≤≤
≥≥

≥ 28 dB

≥≥
≥≥

≥ 17 dB

≥≥

≤≤

≤ 66 dB

≤≤
≤≤

≤ 66 dB

≤≤
≤≤

≤ 66 dB

≤≤
±±

± 6 dB

±±

µµ

µV

µµ

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)
S/N Ratio (60 dB, IHF wtd) Mono

Stereo
Frequency Response (20 Hz - 15 kHz, 60 dB
Channel Separation (60 dB

Alternate Channel Selectivity (40 dB
Capture Ratio (40 dB
AM Suppression (60 dB
Image Rejection (119.4 MHz)
I.F. Rejection (10.7 MHz)
Pilot Suppression (98 MHz)
THD (60 dBµ, L=R 75 kHz for AH, 40 kHz Dev for C) Mono

Auto-Search Sensitivity On

RDS decode Sensitivity

µµ

µ, 100% Mod. FM, 30% Mod. AM)

µµ

µµ

µ) 100 Hz

µµ

µµ

±±

µ,

± 400 kHz)

µµ

±±

µµ

µ)

µµ

µµ

µ) 0

µµ

1 k

10 kHz

Stereo

Off

≤≤

≤ 15 dB

≤≤
≥≥

≥ 63 dB

≥≥
≥≥

≥ 63 dB

≥≥

≥≥

≥ 30 dB

≥≥
≥≥

≥ 38 dB

≥≥
≥≥

≥ 30 dB

≥≥
≥≥

≥ 60 dB

≥≥
≤≤

≤ 3 dB

≤≤
≥≥

≥ 48 dB

≥≥

−−

−

−−
≥≥

≥ 78 dB

≥≥
≥≥

≥ 60 dB

≥≥
≤≤

≤ 0.25 %

≤≤
≤≤

≤ 0.35 %

≤≤
≥≥

≥ 24 dB

≥≥
≤≤

≤ 15 dB

≤≤
≤≤

≤ 26 dB

≤≤

µµ

µ

µµ

±±

± 1.5 dB 0

±±

µµ

µ

µµ
µµ

µ

µµ
µµ

µ

µµ

≤≤

≤ 15 dB

≤≤
≥≥

≥ 63 dB

≥≥
≥≥

≥ 63 dB

≥≥

≥≥

≥ 30 dB

≥≥
≥≥

≥ 38 dB

≥≥
≥≥

≥ 30 dB

≥≥
≥≥

≥ 45 dB

≥≥
≤≤

≤ 3 dB

≤≤
≥≥

≥ 48 dB

≥≥
≥≥

≥ 65 dB

≥≥

−−

−

−−
≥≥

≥ 60 dB

≥≥
≤≤

≤ 0.25 %

≤≤
≤≤

≤ 0.35 %

≤≤
≥≥

≥ 24 dB

≥≥
≤≤

≤ 15 dB

≤≤

−−

−

−−

±±

± 1.5 dB

±±

µµ

µv

µµ

µµ

µ

µµ
µµ

µ

µµ

PHYSICAL SPECIFICATIONS

Dimensions (Width x Height x Depth) 435 x 170 x 423 mm
Net Weight 20.50 Kg (45.10 lbs)
Shipping Weight 24.0 Kg (52.80 lbs)

5

REAR PANEL / FRONT PANEL VIEW

REAR PANEL

1. FM & AM ANTENNA

2. SOFT CLIPPING ON/OFF

3. MONITOR OUT

4. CD INPUT

5. IR INPUT & OUTPUT

6. +12V TRIGGER INPUT & OUTPUT

7. COMPONENT VIDEO IN &
COMPONENT VIDEO OUT

8. DIGIT AL AUDIO INPUT &
DIGITAL AUDIO OUTPUT

FRONT PANEL

9. POWER SWITCH

10. SWITCHED AC OUTLETS
1 1. AC POWER INLET

12. SPEAKERS A & B

13. DVD, SA T, VCR, VIDEO 4 & VIDEO 5

14. MAIN IN / AUDIO PRE-OUTS /
SUBWOOFER OUT

15. T APE INPUT & OUTPUT

16. MS OUT (MUL TISOURCE OUT)

17. 7.1 CH. INPUTS

1. STANDBY SWITCH

2. STANDBY LED

3. AM / FM

4. FM MUTE / MODE

5. DISPLAY

6. MEMORY

7. PRESET DOWN / UP

8. SEARCH DOWN / UP

9. VFL DISPLAY

10. VOLUME (SETUP)
1 1. SOURCE DOWN / UP

12. SURROUND MODE

6

13. LEVELS

14. TONE DEFEA T

15. TONE CONTROLS

16. SPEAKERS A & B

17. VIDEO 6 INPUT

18. PHONES

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.

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 indicated by the arrow 12. Refer to Figure No. 2.

Figure No. 2

7

WIRING DIAGRAM

THERM SENSNOR

TO MAIN BOARD

J901A

RS232 BOARD

82-0426135-01-XX

CABLE ASSY 4 WAYS #26

J414B

COMPONENT VIDEO

J712B

TUNER

30

J711B

1211

33

35

J350A

15

TRIGGER BOARD

TO MAIN BOARD

J710B

J712A

J6105A

J704A

J720A

J6106A

J6106A J6105A

J6103A

PRE-OUT BOARD MULTI-CHANNEL

J611A

J612A

J719A

J711A

J707A

J717A

J6102A

J710A

J719B

J6101A

TO MAIN BOARD

J715A

J701

J502B

J6104A

J717B

J350B

MAIN BOARD

J6101B

J713A J714A

J709A

J8101B

DIGITAL BOARD

6

TO MAIN BOARD

J707B

J708B

32

34

J203B

J1009A

J1009B

J1010A

J1010B

DSP BOARD

7

VIDEO BOARD

J604B

J715B

13

8

J201

23

24

J203A

J713B J714B

36

J704B

AUDIO BOARD

J6103B

J501B1

J501B3

J501B5

J582A1

J582A3

J582A5

J582A1

J582A3

J582A5

SPEAKER A

J504B1

J504B3

J782A1

J782A2

J782A3

S-VIDEO BOARD

TO MAIN BOARD

J6102B

21

20

19

22

18

J3103A

J414A

J582A

J801A

27

J753B

29

KEYBOARD

J901B

J204A

LED BOARD

J3103B

P4402

J709B

2625

9

VIDEO 6 INPUT BOARD

31

J757B

J758B

BOARD

POWER SWITCH

10

THERM SENSNOR

M506

AMP 1 BOARD

J511A

J504A

J801A

38

37

MOUNT ON

CHASSIS GND

39

J757 J756

J758

J761_N J761_L

J759

J760

J501A

J581B

J754B

J751B

PSU BOARD

(FRONT & CENTER)

3

AMP 2 BOARD

(SURROUND AMP.)

J753A

J611B

J781B

J581A

J503A

J503B

J502A

ISC BOARD

J612B

J511B

J783A1

J784A

J803B

J801B

16

J204B

2

17

4

1

J8101A

5

28

14

J782A

J781A

J803A

SECONDARY BOARD

SPEAKER B

USE J760

UL VERSION :

CE VERSION :

USE J758, J759

FROM TRANSFORMER

8

WIRING DIAGRAM PARTS LIST

Item Database Part Number Description Remark

1 17-012-2986-90

2 17-012-2987-90

3 17-012-2988-90

4 17-012-2989-90

5 17-012-2966-90 CABLE ASSY 4 WAYS AWG26 2.5P UL1533 L=450MM

6 17-012-2957-90

7 17-012-2990-90

8 17-012-2956-90

9 17-012-3404-90 CABLE ASSY 5 WAYS AWG26 2.5P UL1007 L=160mm LED BD-J204A

10 17-012-2991-90

11 17-012-2963-90 CABLE ASSY 3 WAYS AWG=26 2.5P L=110mm

12 17-012-2992-90 CABLE ASSY 3 WAYS AWG=26 2.5P L=60mm

CABLE ASSY 2 WAYS AWG=26 2.5P UL2468
L=440mm

CABLE ASSY 4 WAYS AWG=18 3.96P UL1007
L=420mm

CABLE ASSY 6 WAYS AWG=26 2.5P UL1007
L=320mm

CABLE ASSY 4 WAYS AWG=18 3.96P UL1007
L=200mm REV.B

CABLE ASSY 2 WAYS AWG=26 2.5P UL1533
L=540mm

CABLE ASSY 4 WAYS AWG=26 2.5P UL2468
L=540mm

CABLE ASSY 1 WAY AWG18 UL1007 BLACK
L=100mm W/ RING TERMINAL

CABLE ASSY 1 WAY AWG=18 UL1007 BLACK
L=360mm W/ RING TERMINAL

AMP1 BD-J511A

AMP1 BD-J581A

AMP1 BD-J503A

AMP2 BD-J781B

AUDIO BD­J3103A

DIGIT BD­J1009A

DIGITAL BD­J1010A

KEYBOARD­J201

MAIN BD-J701

MAIN BD­J6106B

MAIN BD­J6105B

13 17-012-2964-90 CABLE ASSY 3 WAYS AWG26X2C UL2547 L=210mm MAIN BD-J715A

14 17-012-2974-90 CABLE ASSY 8 WAYS AWG=26X3C L=480mm MAIN BD-J709A

15 17-012-2993-90 CABLE ASSY 10 WAYS AWG26 2.5P UL1007 L=460mm MA BD-J350B

16 17-012-2977-90 CABLE ASSY 12 WAYS AWG26 2.5P UL2468 L=230mm MA BD-J502B

17 17-012-2994-90 CABLE ASSY 14 WAYS #26 2.5P UL1007 L=540mm MA BD-J8101B

18 17-012-2960-90

19 17-012-2995-90

20 17-012-2996-90

21 17-012-2997-90

22 17-012-2998-90

23 17-012-2972-90

CABLE ASSY 3 WAYS AWG=18 3.96P UL1015
L=320mm

CABLE ASSY 3 WAYS AWG=18 3.96P UL1015
L=350mm

CABLE ASSY 5 WAYS AWG=18 3.96P UL1007
L=250mm (V/BL/Y)

CABLE ASSY 5 WAYS AWG=18 3.96P UL1007
L=120mm (BR/R/O)

CABLE ASSY 3 WAYS AWG=18 3.96P UL1015
L=240mm

CABEL ASSY 6 WAYS AWG=26 2.5P UL1533X1C
L=350mm

SPK BD-J782B1,
J782B2,J782B3

SPK BD-J582B1,
J582B2,J582B3

SPK BD-J801B1,
J801B3,J801B5

SPK BD-J501B1,
J501B3,J501B5

SPK BD-J504B1,
J504B3

PO BD-J612A

9

Item

Database Part Number Description Remark

24 17-012-2999-90

25 17-012-2948-90

26 17-012-2874-90 CABLE ASSY 1 WAY AWG=16 UL1672 BLUE L=100mm PS BD-J756

27 17-012-2965-90 CABLE ASSY 4 WAYS AWG26 2.5P UL2468 L=400mm PS BD-J753A

28 17-012-3000-90 CABLE ASSY 2 WAYS AWG=18 UL1007 L=170MM SE BD-J803A

29 17-012-3001-90 CABLE ASSY 6 WAYS #18 3.96P UL1007 L=150MM SE BD-J801A

30 17-012-2973-90

31 17-012-2956-90

32 17-010-0032-90

33 17-010-0033-90

34 17-010-0038-90 FFC CABLE 20 PINS P1.25 L=160mm W/ SHIELD

CABLE ASSY 6 WAYS AWG=26 2.5P UL 1533X1C
L=540mm

CABLE ASSY 1 WAY AWG=16 UL1672 BROWN
L=100mm

CABLE ASSY 8 WAYS AWG=26 2.5P UL1007
L=380mm

CABLE ASSY 1 WAY AWG18 UL1007 BLACK
L=100mm W/ RING TERMINAL

FFC CABLE 30 PINS P1.25 L=70mm W/SHIELD

FFC CABLE 17 PINS P1.25 L=200mm W/ SHIELD

PO BD-J611A

PS BD-J757

SV BD-J414A

V6 BD-P4402

J601C

J720C

J604C

35 17-010-0039-90 FFC CABLE 28 PINS P1.25 L=170mm W/ SHIELD J602C,J603C

36 17-010-0040-90 FFC CABLE 30 PINS P1.25 L=220mm W/ SHIELD J713C,J714C

37 17-012-2875-90

38 17-012-2948-90

39 17-012-2874-90 CABLE ASSY 1 WAY AWG=16 UL1672 BLUE L=100mm

CABLE ASSY 1 WAY AWG=16 UL 1015
GREEN/YELLOW L=100mm

CABLE ASSY 1 WAY AWG=16 UL1672 BROWN
L=100mm

1-CHASSIS GND

1-INLET/PSU.BD
(L),J759

1-INLET/
PSU.BD,J758

10

BLOCK DIAGRAM

T

T

T

T

T

COAX / OPT

OUT

COAX IN

OPT IN

Ex FRONT

Ex SURR

Ex BSURR

Ex CEN

Ex SUB

TUNER

AUDIO

TAPE

OUT

TAPE

IN

IN

IN

IN

IN

IN

V3
OUT

V4
OUT

V1

V2

V3

V4

V5

V6

CD

IN

CPU

74HC251

DSP SECTION

CPU

CS-8415

DIR

CDIN
CCLK
CDOUT
CS
RESET

CPU

74HC157

CDIN

CPU

CCLK
CDOUT
CS
RESET
INTREG

LEVEL LEVEL
SHIFTER SHIFTER
74HC245 74HC245

D/A

CS4228

96/24

C

SSRSL FRBSL

VOLUME

ENCODE

TRIGGER

IN/OUT

IR
IN

KEY

MATRIX

HCF4094

DSP

CS-49326

LEVEL
SHIFTER
74HC245

BSR

ELECT

VOLUME /

AUDIO

SELECTOR

M61516

ELECT

VOLUME /

AUDIO

SELECTOR

M61516

74HC574

D/A
CS4340
96/24

EEPROM

24C16

CPU

T89C51RD2

A15

CPU

A16
A17

EPROM

256k x8

W27C02

CPU

BASS

RE-DIRECT

FL

V1

V2

V3

V4

V5

V6

VIDEO

IN

(COMPOSITE/S)

VIDEO

IN

(COMPONENT)

V1

V2

SR

SL

SUB

C

FR

FL

BSR

BSL

MSR

MSL

MUTE

MUTE

MUTE

MUTE

MUTE

MUTE

MUTE

MUTE

MS AUDIO

OUT

SELECTOR

74HC4051

LC74763

MULTI-

PLEXER

74HC4052

75 OHM
DRIVER

BA7660FS

74HC00 74HC04

EXT 7.1

SR

SUB

SL

BSR

PRE-OUT

C

BSL

FR

FL

FR

FL

C

SR

SL

BSL

VIDEO

OSD

IN

POWER

AMP

POWER

AMP

CPU

V3 OUT

V4 OUT

CPU

CPU

MON OUT

VIDEO OUT

(COMPONENT)

FR

RELAY

FL

FR

RELAY

FL

C

RELAY

SR

RELAY

SL

RELAY

BSL

SPK
OU

SPK
OU

SPK
OU

SPK
OU

SPK
OU

(B)

(A)

RST IC
TCM810

74HC

4051

CPU

T89C51RD2

74VHC

245

DATACLK

CS4228
CS4340
CS49326
CS8415A
LC74763
M61516

VFD

VFD DRIVER

PT6306

11

ARRAY OF

SHIFT REGISTERS

HCF4094

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 + MEMORY
VFD ALL DISPLAY AUDIO 6 + TONE DEFEAT
AM FREQ. STEP AM/FM + FM MUTE

DETAILS & WAVEFORMS ON SYSTEM TEST & DEBUGGING

M6759(U202) main clock is at 20MHz(X202)

UPPER - OUTPUT ENABLE(pin 24) of EPROM
(W27C02) when changing SURROUND MODES

LOWER - CHIP ENABLE(pin 22) of EPROM
(W27C02) when changing SURROUND MODES

M6759(U201) main clock is at 20MHz(X201)

UPPER - +5V supply to KEYBOARD when power up
LOWER - RESET line (TCM810LENB713) when

power up

SCLK (pin 43 of CS49326)

LRCLK (pin 42 of CS49326)

MCLK (pin 30 of CS49326)

NOTE: The waveforms are based on software version V2.10.

12

ADJUSTMENT POINT DIAGRAM

FRONT / CENTER AMPLIFIER BOARD

R522 R545 R571

P501

P502 P503

SURROUND AMPLIFIER BOARD

R835 R836 R897

P802P801

P803

SECONDARY / ISC BOARD

R881

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 5 min, and check for idle current again.

6. Repeat for other channels.

CHANNEL JUMPER VR

FL P501 R522
FR P502 R545
C P503 R571
SL P801 R835
SR P802 R836
BS P803 R897

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,BS output. Clipping should occur before full power
achieved.

5. Rotate R834 counter-clockwise slowly until the THD just below 0.1%.

6. Repeat step 2-5 for R834 but monitor FL, FR & Center output.

7. The procedure is finish at this step.

8. Load all channels at full power using 1kHz sine wave with 4 ohm load.

9. The clipping power(at THD 0.1%) should less than 85W.

13

PCB LAYOUT

AUDIO BOARD

POWER SUPPLY (STANDBY) BOARD

14

COMPONENT VIDEO BOARD - COMPONENT SIDE

COMPONENT VIDEO BOARD - COPPER SIDE

DIGITAL BOARD - COMPONENT SIDE SIDE

DIGITAL BOARD - COPPER SIDE

15

DSP BOARD - COMPONENT SIDE

DSP BOARD - COPPER SIDE

16

FRONT / CENTER AMPLIFIER BOARD - COMPONENT SIDE

17

FRONT / CENTER AMPLIFIER BOARD - COPPER SIDE

18

SURROUND AMPLIFIER BOARD - COMPONENT SIDE

19

SURROUND AMPLIFIER BOARD - COPPER SIDE

20

KEY BOARD/POWER SWITCH

- COMPONENT SIDE

KEY BOARD/POWER SWITCH

- COPPER SIDE

21

MAIN BOARD

22