NAD T-742 Service manual

NAD

T 742

SURROUND

SOUND RECEIVER

T 742

SURROUND

SOUND RECEIVER

SERVICE MANUAL

PRODUCT SAFETY SERVICING GUIDELINES

CAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN
ANY WAY. NEVER PERFORM CUSTOMIZED INSTALLATIONS
WITHOUT MANUFACTURER’S APPROVAL. UNAUTHORIZED
MODIFICATIONS WILL NOT ONLY VOID THE WARRANTY, BUT
MAY LEAD TO YOUR BEING LIABLE FOR ANY RESULTING
PROPERTY DAMAGE OR USER INJURY.

SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU
ARE THOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING
SAFETY CHECKS AND SERVICING GUIDELINES. TO DO
OTHERWISE, INCREASES THE RISK OF POTENTIAL HAZARDS
AND INJURY TO THE USER.

WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR
PROTECTION FROM AC LINE SHOCK.

SAFETY CHECKS

AFTER THE ORIGINAL SERVICE PROBLEM HAS BEEN
CORRECTED. A CHECK SHOULD BE MADE OF THE
FOLLOWING.

SUBJECT : FIRE & SHOCK HAZARD

1. BE SURE THAT ALL COMPONENTS ARE POSITIONED IN
SUCH A WAY AS TO AVOID POSSIBILITY OF ADJACENT
COMPONENT SHORTS. THIS IS ESPECIALLY IMPORTANT
ON THOSE MODULES WHICH ARE TRANSPORTED TO AND
FROM THE REPAIR SHOP.

2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVE
DEVICES SUCH AS INSULATORS, BARRIERS, COVERS,
SHIELDS, STRAIN RELIEFS, POWER SUPPLY CORDS, AND
OTHER HARDWARE HAVE BEEN REINSTALLED PER
ORIGINAL DESIGN. BE SURE THAT THE SAFETY PURPOSE
OF THE POLARIZED LINE PLUG HAS NOT BEEN DEFEATED.

3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLE
COLD SOLDER JOINTS, SOLDER SPLASHES OR SHARP
SOLDER POINTS. BE CERTAIN TO REMOVE ALL LOOSE
FOREIGN PARTICLES.

4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR
DETERIORATION TO PARTS AND COMPONENTS. FOR
FRAYED LEADS, DAMAGED INSULATION (INCLUDING AC
CORD). AND REPLACE IF NECESSARY FOLLOW ORIGINAL
LAYOUT, LEAD LENGTH AND DRESS.

5. NO LEAD OR COMPONENT SHOULD TOUCH A RECEIVING
TUBE OR A RESISTOR RATED AT 1 WATT OR MORE. LEAD
TENSION AROUND PROTRUDING METAL SURFACES MUST
BE AVOIDED.

6. ALL CRITICAL COMPONENTS SUCH AS FUSES,
FLAMEPROOF RESISTORS, CAPACITORS, ETC. MUST BE
REPLACED WITH EXACT FACTORY TYPES, DO NOT USE
REPLACEMENT COMPONENTS OTHER THAN THOSE
SPECIFIED OR MAKE UNRECOMMENDED CIRCUIT
MODIFICATIONS.

7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM AN
AC LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OF
THE CABINET, (THE CHANNEL SELECTOR KNOB, ANTENNA
TERMINALS. HANDLE AND SCREWS) TO BE SURE THE SET
IS SAFET TO OPERATE WITHOUT DANGER OF ELECTRICAL
SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER
DURING THIS TEST USE AN AC VOLTMETER, HAVING 5000
OHMS PER VOLT OR MORE SENSITIVITY, IN THE
FOLLOWING MANNER; CONNECT A 1500 OHM 10 WATT
RESISTOR, PARALLELED BY A .15 MFD, 150V AC TYPE
CAPACITOR BETWEEN A KNOWN GOOD EARTH GROUND
(WATER PIPE, CONDUIT, ETC.) AND THE EXPOSED
METALLIC PARTS, ONE AT A TIME.
MEASURE THE AC VOLTAGE ACROSS THE COMBINATION
OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR.
REVERSE THE AC PLUG AND REPEAT AC VOLTAGE
MEASUREMENTS FOR EACH EXPOSED METALLIC PART.

VOLTAGE MEASURE MUST NOT EXCEED 75 VOLTS R.M.S.
THIS CORRESPONDS TO 0.5 MILLIAMP AC ANY VALUE
EXCEEDING THIS LIMIT CONSTITUTES A POTENTIAL
SHOCK HAZARD AND MUST BE CORRECTED IMMEDIATELY.

SUBJECT : GRAPHIC SYMBOLS

SUBJECT : TIPS ON PROPER INSTALLATION

1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS,
CUBBYHOLE OR CLOSELY FITTING SHELF SPACE. OVER
OR CLOSE TO HEAT DUCT, OR IN THE PATH OF HEATED
AIR FLOW.

2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS:
OUTDOOR PATIO INSTALLATIONS WHERE DEW IS A
FACTOR, NEAR STEAM RADIATORS WHERE STEAM
LEAKAGE IS A FACTOR, ETC.

3. AVOID PLACEMENT WHERE DRAPERIES MAY OBSTRUCT
REAR VENTING. THE CUSTOMER SHOULD ALSO AVOID THE
USE OF DECORATIVE SCARVES OR OTHER COVERINGS
WHICH MIGHT OBSTRUCT VENTILATION.

4. WALL AND SHELF MOUNTED INSTALLATIONS USING A
COMMERCAL MOUNTING KIT MUST FOLLOW THE FACTORY
APPROVED MOUNTING INSTRUCTIONS A PRODUCT
MOUNTED TO A SHELF OR PLATFORM MUST RETAIN ITS
ORIGINAL FEET (OR THE EQUIVALENT THICKNESS IN
SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS
THE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERS
MUST NOT TOUCH ANY PARTS OR WIRING. PERFORM
LEAKAGE TEST ON CUSTOMIZED INSTALLATIONS.

5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A
PRODUCT ON SLOPING SHELF OR A TILTED POSITION,
UNLESS THE PRODUCT IS PROPERLY SECURED.

6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE
ON ITS MOUNTING TO THE CART. CAUTION THE
CUSTOMER ON THE HAZARDS OF TRYING TO ROLL A CART
WITH SMALL CASTERS ACROSS THRESHOLDS OR DEEP
PILE CARPETS.

7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR
STAND WHICH HAS NOT BEEN LISTED BY UNDERWRITERS
LABORATORIES, INC. FOR USE WITH THEIR SPECIFIC
MODEL OF TELEVISION RECEIVER OR GENERICALLY
APPROVED FOR USE WITH T.V.’S OF THE SAME OR
LARGER SCREEN SIZE.

8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION
CORDS, EXPLAIN THAT A FOREST OF EXTENSIONS
SPROUTING FROM A SINGLE OUTLET CAN LEAD TO
DISASTROUS CONSEQUENCES TO HOME AND FAMILY.

THE LIGHTNING FLASH WITH ARROWHEAD SYMBOL, WITHIN AN
EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE USER TO THE
PRESENCE OF UNINSULATED “DANGEROUS VOLTAGE” WITHIN THE
PRODUCT’S ENCLOSURE THAT MAY BE OF SUFFICIENT MAGNITUDE TO
CONSTITUTE A RISK OF ELECTRIC SHOCK.

THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS
INTENDED TO ALERT THE USER TO THE PRESENCE OF IMPORTANT
OPERATING AND MAINTENANCE (SERVICING) INSTRUCTIONS IN THE
LITERATURE ACCOMPANYING THE APPLIANCE.

SERVICING PRECAUTIONS

CAUTION : Before servicing the A/V Receiver covered by this
service data and its supplements and addends, read and follow the
SAFETY PRECAUTIONS. NOTE : if unforeseen circumstances
create conflict between the following servicing precautions and any
of the safety precautions in this publication, always follow the safety
precautions.

Remember Safety First:

General Servicing Precautions

1. Always unplug the A/V Receiver AC power cord from the AC
power source before:
(1) Removing or reinstalling any component, circuit board,

module, or any other assembly.

(2) Disconnecting or reconnecting any internal electrical plug or

other electrical connection.

(3) Connecting a test substitute in parallel with an electrolytic

capacitor.

Caution : A wrong part substitution or incorrect polarity installation
of electrolytic capacitors may result in an explosion hazard.

2. Do not spray chemicals on or near this A/V Receiver or any of its
assemblies.

3. Unless specified otherwise in this service data, clean electrical
contacts by applying an appropriate contact cleaning solution to
the contacts with a pipe cleaner, cottontipped swab, or
comparable soft applicator.
Unless specified otherwise in this service data, lubrication of
contacts is not required.

4. Do not defeat any plug/socket B+ voltage interlocks with which
instruments covered by this service manual might be equipped.

5. Do not apply AC power to this A/V Receiver and/or any of its
electrical assemblies unless all solid-state device heat sinks are
correctly installed.

6. Always connect test instrument ground lead to the appropriate
ground before connecting the test instrument positive lead. Always
remove the test instrument ground lead last.

Insulation Checking Procedure

Disconnect the attachment plug from the AC outlet and turn the
power on. Connect an insulation resistance meter(500V) to the
blades of the attachment plug. The insulation resistance between
each blade of the attachment plug and accessible conductive parts
(Note 1) should be more than 1M-ohm.
Note 1 : Accessible Conductive Parts including Metal panels, Input
terminals, Earphone jacks, etc.

Electrostatically Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by
static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical Es
devices are integrated circuits and some field effect transistors and
semiconductor chip components.
The following techniques should be used to help reduce the
incidence of component damage caused by static electricity.

1. Immediately before handling any semiconductor component or
semiconductor-equipped assembly, drain off any electrostatic
charge on your body by touching a known earth ground.
Alternatively, obtain and wear a commercially available
discharging wrist strap device, which should be removed for
potential shock reasons prior to applying power to the unit under
test.

2. After removing an electrical assembly equipped with ES devices,
place the assembly on a conductive surface such as aluminum
foil, to prevent electrostatic charge buildup or exposure of the
assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ES
devices.

4. Use only an antistatic solder removal device. Some solder
removal devices not classified a “anti-static” can generate
electrical charges sufficient to damage ES devices.

5. Do not use freonpropelled chemicals. These can generate
electrical charge sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective
package until immediately before you are ready to install it. (Most
replacement ES devices are packaged with leads electrically
shorted together by conductive foam, aluminum foil, or
comparable conductive material).

7. lmmediately before removing the protective material from the
leads of a replacement ES device, touch the protective material to
the chassis or circuit assembly into which the device will be
installed.

Caution : Be sure no power is applied to the chassis or circuit, and
observe all other safety precautions.

8. Minimize bodily motions when handing unpackaged replacement
ES devices. (Normally harmless motion such as the brushing
together of your clothes fabric or the lifting of your foot from a
carpeted floor can generate static electricity sufficient to damage
an ES device.)

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 No Part Number Description

M270 *AH 5120-0200-0 5A TIME-LAG 5x20 UL/CSA
M271 *C 5120-0024-0 3.15A TIME-LAG 5x20 VDE-SEMKO
M272 *AH 5120-0052-0 1.6A TIME-LAG 5x20 UL/CSA

NOTE:

<*AH > : USA, CANADIAN MODEL ONLY.
<*C > : 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 the supply circuit.

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4

REAR PANEL / FRONT PANEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

DISASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-8

BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

ADJUSTMENT POINTS DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-11

INSTRUMENT SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

ALIGNMENT PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-13

IMPORTANT NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

PCB LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14-24

SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25-42

IC BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43-51

ELECTRICAL PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52-71

EXPLODED VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

EXPLODED VIEW PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73-74

PACKING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

3

SPECIFICATIONS

POWER AMPLIFIER AND PREAMPLIFIER SECTION (all channels stated 8 ohms)

Rated distortion (THD 20Hz-20 kHz FL/C/FR) ≤ 0.08%

(THD 20Hz-20 kHz SL/SR) ≤ 0.3%
Input Sensitivity (ref. 8 ohms, 1 kHz) 180+/-30 mV
S/N Ratio (A-wtd, 1KHz, 1W, 8 ohm) ≥ -78 dB

(A-wtd, 1KHz, 80W, 8 ohm) FL/FR/C ≥ 92 dB

SL/SR ≥ -90 dB
Frequency Response (20 Hz - 20 kHz) 0 ± 0.8 dB
Channel Balance (1 dB to -40 dB, 1 kHz) ≤ 2 dB

(-41 dB to -50 dB, 1 kHz) ≤ 3 dB
Audio muting at 1kHz ≥ 53 dB
Headphone O/P in 0.1%, 600 ohm load, CD in 500mV, 1 kHz ≥ 10V
Subwoofer out, 500mV in (THD at 2V O/P, 100 Hz) ≥ 0.5%

(S/N at 2V O/P, 100 Hz) ≥ 80 dB
Crosstalk (2V input, 10W, 1 kHz) > -68 dB
Continuous average power output (L/R/C RL/RR 8 ohms) 50 W

Controls

Bass (at 500mV in, 1W out, 100 Hz) ±9 dB
Treble (at 500mV in, 1W out, 10 kHz) ±9 dB

SURROUND SECTION
Channel separation

I/p mode : L, R : 1V in, 1 kHz, Ch R, L ≥ 45 dB

: o/p at unexpected, 1 kHz, Ch C ≥ 35 dB

I/p mode : L= -R : 1V in, 1 kHz, Ch R, L ≥ 28 dB

: o/p at unexpected, 1 kHz, Ch C ≥ 30 dB

I/p mode : L= R : 1V in, 1 kHz, Ch R, L ≥ 45 dB

: o/p at unexpected, 1 kHz, Ch SL, SR ≥ 30 dB

Frequency Response

I/p mode : L, R : 1V in, 1W, Ch R, L 40Hz 0 ± 1.5 dB

20kHz 0 ± 1.5 dB
I/p mode : L= R : 1V in, 1W, Ch C 300Hz 0 ± 0.8 dB

20kHz 0 ± 0.8 dB
I/p mode : L= -R : 1V in, 1W, Ch SL, SR 30Hz 0 ± 1.0 dB

6.5kHz -3 ± 1.0 dB
S/N Ratio ( 200mV in, 1, A-WTD w/ 1k 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 (2.2V in, 1W, w/ 80 kHz LPF, 1 kHz) ≤ 0.2%

DTS SECTION
Frequency Response

FL, FR, C, SL, SR: 200Hz 0 ± 0.8 dB

20kHz 0 ± 0.8 dB

Distortion 1W all channels 0.08%

4

AM TUNER SECTION

Input level is expressed as the reading in open-circuit
of 75-ohm source impedance signal generator
Usable sensitivity (999/1000kHz) ≤ 30 dBµ
S/N Ratio (5mV in) ≥ 38 dB
THD (5mV in) ≤ 3%
IF Rejection (450 kHz) ≥ 45 dB
Image Rejection (F+2xIF) ≥ 28 dB
Selectivity ≥ 17 dB
Output 130+/- 20mV
Loop sensitivity (20dB S/N)

999/1000 kHz ≤ 66 dB
603/600 kHz ≤ 66 dB
1404/1400 kHz ≤ 66 dB

Frequency response (100 - 2.3 kHz, 5mV) ± 6 dB

FM TUNER SECTION

*C

Input level is expressed as the reading in open-circuit
of 75-ohm source impedance signal generator
Usable Sensitivity ( 98 MHz) ≤ 15 dBµ
Signal / Noise Ratio Mono ≥ 72 dB

(60 dBµ, IHF wtd) Stereo ≥ 66 dB
Frequency Response (20 Hz - 15 kHz, 60 dBµ) 0 ± 1.5 dB
Channel Separation (60 dBµ) 100 Hz ≥ 30 dB

1 kHz ≥ 40 dB
10 kHz ≥ 30 dB

Alternate Channel Selectivity

(40 dBµ, ±400 kHz) ≥ 60 dB
Capture Ratio (40 dBµ) ≤ 3 dB
AM Suppression

(60 dBµ, 100% Mod.FM, 30% Mod.AM) ≥ 48 dB
Image Rejection (119.4 MHz) ≥ 68 db
I.F. Rejection ( 10.7 MHz) ≥ 78 dB
Pilot Suppression (60 dBµ) ≥ 60 dB
THD (60 dBµ, L=R 75 kHz for AH, 40 kHz Dev for C)

Mono ≤ 0.25%
Stereo ≤ 0.35%

Auto-Search Sensitivity On ≥ 24 dBµ

Off ≤ 15 dBµ

RDS decode Sensitivity ≤ 26 dBµ

POWER RA

TING

EUROPEAN Model *C AC 230V~ 50Hz 1.2A
USA, CANADIAN Model *AH AC 120V~ 60Hz 2.5A

PHYSICAL

SPECIFICATIONS

Dimensions (Width x Height x Depth) 435 x 131 x 348mm
Net weight 14kg (31 lbs)
Shipping weight 16.7kg (37 lbs)

5

REAR PANEL / FRONT PANEL

REAR PANEL

FRONT PANEL

1. FM & AM ANTENNA

2. TAPE 1 & CD INPUTS

3. 5.1 CHANNEL INPUTS

4. DVD - SAT VCR - VIDEO 4 (AUDIO &
VIDEO)

5. DIGITAL AUDIO INPUTS

6. AUDIO PRE OUTS / SUBWOOFER OUT

7. MONITOR OUT

8. SPEAKERS: FRONT, CENTER & SUR­ROUND SPEAKERS

9. SOFT CLIPPING

10. IR INPUT

11. AC POWER CORD

12. 12 VOLT TRIGGER OUT

1. POWER

2. STAND-BY INDICATOR

3. DISPLAY

4. FM/AM

5. FM MUTE / MODE

6. MEMORY

7. PRESET / TUNE

8. DOWN / UP AND

9. VFL DISPLAY

10. VOLUME & SETUP

11. HEADPHONE SOCKET & VIDEO 5 INPUT

12. AUDIO & VIDEO INPUT SELECTORS

13. CD

14. TAPE MONITOR

15. EXT. 5.1

16. SURROUND MODE

17. SET UP

18. TONE CONTROLS

6

DISASSEMBLY INSTRUCTIONS

1. Remove machine screws M 4.0 x 6.0 ( 1 to 6 ) from the side panels.

Remove tapping screw 3.0 x 8.5 ( 7 )from the back panel.

Refer to Figure No.1.

Figure No.1

2. Pull both sides of the TOP COVER slightly outwards 8 and tilt approx. 35˚ and then remove

in the direction as indicated by the arrow 9 . Refer to Figure No.2.

Figure No.2.

7

6

5

1

3

2

4

9

8

8

87

P702

P701

POWER SWITCH PCB

J401A

AC3 PCB

J203B

J101A

J604B

J601B

J208A

J208B

J203A

J206A

J207A

J207B

SECONDARY PCB

J701A J202B

J206A

JP210
JP211

J702B

JP210

J602B

T201A

T202A

JP207

JP206

M704B

C230

JP209

JP203

J206B

JP204

JP205

C221

P261

P260

P262

J101B

J203B

J202A

J201B

P264

PSU PCB

P266

P265

DIGITAL PCB

P261

SPEAKER PCB

P262 P260

POWER CORD

L

N

M705A

JP212B

J206B

J705B

J702A

J701B

MAIN PCB

-35V

J705B

J602A

J601A

J706B

+35V

GND

J401B

M708A

M707A

J604A

J704A

J706B

J709B

J714A

J716A

J715A

J710B

JP207B

J703A

J710B J709B

J704B

J703B

J715B

J714B

J716B

VIDEO 5 PCB

POWER LED PCB

KEYBOARD

J202A J201A

VOL PCB

S-VIDEO PCB

PRIMARY PCB

AMPLIFIER PCB

SURROUND

MULTI CHANNEL PCB

TUNER PCB

AUDIO PCB

VIDEO PCB

SHOWN THE PIN 1 OF WIRE HARNESS

SHOWN THE WAFERS

SHOWN THE SOLDER END OF HARNESS

NOTES :

WIRING DIAGRAM

9 10

OSC RF

VT

BLOCK DIAGRAM

COAXIAL x2

OPTICAL x1

74HC153

4053

74LS157

M62446FP

S-Video

Selector

CD4052

TEMPERATURE

PROTECTION

TUNER

L

TUNER

R

POWER DOWN

Detect Pin.

For SPK off,

Mute ON, VFD off.

FL

Trigger out

IR IN

FL

OUT2

OUT3

OUT1

OUT4

FR

CENTERSLSR

SUB

FR

CENTERSLSR

SUB

Video Pin

1 IN 13

2 IN 12

3 IN 15

4 IN 14

5 IN 1

3 OUT 3

4 OUT 3

S-Video Pin

CY

1 IN 11 4

2 IN 12 1

3 IN 15 2

3 OUT 13 3

Video

Selector

CD4051

ADJUSTMENT POINTS DIAGRAM

1. TUNER

2. IDLE CURRENT - Front Amplifier & Surround Amplifier Board

11

12

ALIGNMENT PROCEDURES

AMPLIFIER SECTION

Idle Current

Step Item Connection Adjustment Adjust for

1 Front Left Channel Voltmeter to M714 on Main Board VR7703 1mV±0.2mV

2 Front Right Channel Voltmeter to M713 on Main Board VR7702 1mV±0.2mV

3 Center Channel Voltmeter to M712 on Main Board VR7701 1mV±0.2mV

4 Rear Left Channel Voltmeter to TP202 on Surround Amplifier Board VR202 1mV±0.2mV

(PCB N0A00C-AMP2)

5 Rear Right Channel Voltmeter to TP201 on Surround Amplifier Board VR201 1mV±0.2mV

(PCB N0A00C-AMP2)

INSTRUMENT SETUP

1. FM MEASUREMENT

Fig. 1

Fig. 2

2. RDS MEASUREMENT

Fig. 3

3. AM MEASUREMENT

Fig. 4

FM

SIGNAL

GENERATOR

ANTENNA

TERMINAL

OUTPUT

TERMINAL

DISTORTION

ANALYZER

DISTORTION

ANALYZER

AC

VOLTMETER

OSCILLOSCOPE

AC

VOLTMETER

OR

OSCILLOSCOPE

AC

VOLTMETER

OR

OSCILLOSCOPE

OUTPUT

TERMINAL

OUTPUT

TERMINAL

L

R

ANTENNA

TERMINAL

ANTENNA

TERMINAL

ANTENNA

TERMINAL

AM LOOP
ANTENNA

(Accessory)



AM LOOP

ANTENNA



60cm



DIGITAL

MILLIVOLT

METER



VT-J954



FM

SIGNAL

GENERATOR

AM

SIGNAL

GENERATOR

FM

SIGNAL

GENERATOR

RDS

GENERATOR

FM

STEREO

GENERATOR

P-901

DC

MILLIVOLT

METER

UNIT

UNIT

UNIT

UNIT

13

FM/RDS SECTION

- FM mono: 1kHz, 75kHz devi., 60dB/µV

- FM stereo: 1kHz, 67.5kHz devi., 60dB/µV
Pilot signal 19kHz 7.5kHz devi.

OUTPUTS

- Connect the non-inductive type resistor of 8 ohms to the all speaker terminals unless otherwise noted.

Item

FM

IF/RF

Stereo

Distortion

Stereo

Separation

Muting

Level

Signal
output

Step

1

DC voltmeter L941

0±100mV

3

Distortion

analyzer

Distortion

analyzer

Oscilloscope

Oscilloscope

L942

R956

R941

Minimum

Minimum

2 AC voltmeter

IFT on the

front end

IFT on the

front end

Maximum

Maximum

separation

Connection

of instrument

Fig.1 –

–

Fig.2

Fig.2

Fig.1

Channel L
or R 1kHz

99.0MHz
1kHz 75kHz devi.
65dBf (60dB)

99.0MHz Ext.
mod. 65dBf
(60dB)

FM SG

output

Stereo mod­ulator output

Tuning

frequency

99.0MHz

99.0MHz

Channel L
or R 1kHz

99.0MHz Ext.
mod. 65dBf
(60dB)

99.0MHz Ext.
mod.65dBf(60dB)
RDS 2% MOD

99.0MHz 18dB

99.0MHz

99.0MHz

RDS

–

–

–

–

Fig.3

99.0MHz

Output

indicator

Adjustment

point

Adjust

for

Remarks

FM MUTE/MODE
switch: ON/AUTO
Repeat the steps
1 to 3 until no fur­ther adjustment is
necessary.

FM MUTE/MODE
switch: ON/AUTO
Don’t turn more
than +/-180˚

Repeat stereo
distortion and
stereo separation
alignment until
THD at minimum
and separation at
maximum.

Decode the RDS­Program Station.

AM SECTION

AM Modulation: 400Hz, 30%
For AH Version

Step

1–

2

3

530kHz

600kHz

990kHz

600kHz
400Hz 30% mod.
60dB/m

AM SG

output

Tuning

frequency

Output

indicator

Adjustment

point

600kHz
400Hz 30% mod.
60dB/m

AC

voltmeter

AC

voltmeter

Digital

DC

voltmeter

L972

OSC coil

on RF

block L971

RF coil

on RF

block L971

Adjust

for

1.35±0.2V

Maximum

Maximum

Step

1–

2

3

522kHz

or

531kHz

603kHz

999kHz

600kHz
400Hz 30% mod.
60dB/m

AM SG

output

Tuning

frequency

Output

indicator

Adjustment

point

600kHz
400Hz 30% mod.
60dB/m

AC

voltmeter

AC

voltmeter

Digital

DC

voltmeter

L972

OSC coil

on RF

block L971

RF coil

on RF

block L971

Adjust

for

1.3±0.2V (522kHz)

1.35±0.2V (531kHz)

Maximum

Maximum

For C Version

IMPORTANT NOTES

1. Show the software ver­sion

Press “FM/AM” and “EXT

5.1”.

2. Light up all the icon on
the VFL.

Press “FM/AM” and “TONE
CONTROL”.

3. Toggle between 9K and
10K

Press “FM/AM” and “CD”.

4. Clear all tuner presets

Press “TAPE(MON)” and
“VIDEO 1”.

14

PCB LAYOUT

S-VIDEO BOARD

VIDEO-5 BOARD

VOLUME BOARD

15

VIDEO BOARD

TUNER BOARD

16

SURROUND AMPLIFIER BOARD PRIMARY BOARD

SECONDARY BOARD

17

AUDIO BOARD

PSU BOARD

18

MULTI-CHANNEL BOARD - COMPONENT SIDE

19

MULTI-CHANNEL BOARD - SOLDER SIDE

20

MAIN BOARD

2221

AC3 BOARD - COMPONENT SIDE AC3 BOARD - SOLDER SIDE