NAD C-325-BEE Service manual

NAD

1

SERVICE MANUAL

C 325BEE

STEREO

C 325BEE

STEREO

AMPLIFIER

AMPLIFIER

TABLE OF CONTENTS

2

DESCRIPTION PAGE

SERVICE CAUTION………………………………………………………… 3-4

REAR PANEL/FRONT PANEL VIEW………………………………………...5

SPECIFICATIONS………………………………………………………….6-7

WIRING DIAGRAM………………………………………………………………8

BLOCK DIAGRAM……………………………………………………. …….9-14

ALIGNMENT PROCEDURE……………………………………………..15

SCHEMATICS……………………………………………………………….16-19

PCB LAYOUT……………………………………………………………… 20-23

TROUBLE SHOOTING GUIDE…………………......................................24

ELECTRICAL PARTS LIST…………………………………………….25-34

EXPLODED VIEW……………………………………………………………..35

EXPLODED VIEW PARTS LIST……………………………………………...36

PROTECT IC CHANGE ..............……………………………………..……...37

PRODUCT SAFETY SERVICING GUIDELINES

3

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

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.

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.

SERVICING PRECAUTIONS

4

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.)

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SPECIFICATIONS

6

POWER AMPLIFIER SECTION
STEREO MODE

CONTINUOUS AVERAGE POWER 50 W (17 dBW)
OUTPUT INTO 8 OHMS OR 4 OHMS

(Min. power per channel, 20 Hz – 20 kHz,
with no more than rated distortion)

Rated Distortion 0.03%
(THD 20 Hz – 20 kHz)

Clipping power 68 W
(maximum continuous power per channel 4 and 8).

IHF dynamic headroom: at 8 ohms + 3.4 dB

at 4 ohms + 5.0 dB

IHF dynamic power
(maximum short term power per channel)

8 ohms: 110 W (20.4 dBW)
4 ohms: 160 W (22.0 dBW)
2 ohms: 210 W (23.2 dBW)

Damping factor > 100
(ref. 8 ohms 1 kHz)

Input Impedance R = 20 kohms

C = 1 nF

Input sensitivity (for rated output into 8 ohms) 630 mV

Voltage gain 29 dB

Frequency response 20 Hz – 20 kHz

Signal / Noise ratio, A-weighted 100 dB ref. 1 W

THD + Noise < 0.03%
(Total Harmonic Distortion, 20 Hz – 20 kHz,
from 250 mW to rated output)

SMPTE I.M. < 0.01%
(Intermodulation Distortion, 60 Hz + 7 kHz, 4:1,
from 250 mW to rated output)

0.2 dB

117 dB ref. 50 W

IHF I.M. < 0.01%
(CCIF IM Distortion, 19 + 20 kHz at rated output)

Headphones Output Impedance 220 ohms

PREAMPLIFIER SECTION

7

LINE LEVEL INPUTS

(Disk, CD, Video, Auxiliary, Tuner, Tape 1,Tape 2)

Input impedance (R and C) 200 kohms + 320 pF

Input sensitivity (ref. rated power) 220 mV

Maximum input signal 6 V

Signal / Noise ratio, A-weighted 93.0 dB ref. 1W
(from CD Input to Speakers Output, Volume Setting
for 500mV in , 8ohms 1W out)
Signal to noise ratio preamp out, IHF “A” weighted 106 dB re 500mV

Frequency response, 20 Hz – 20 kHz < +/-0.1 dB (tone defeat on)
< +/-0.5 dB (tone defeat off)
THD + Noise, SMPTE IM < 0.01% at 5 V out

LINE LEVEL OUTPUTS

Pre-amp output impedance 80 ohms

Tape output impedance Source Z + 1kohms

Maximum output level pre-amp out : > 12 V
Tape-out : > 10 V

CONTROLS

Treble +/- 5 dB at 10 kHz

Bass +/- 8 dB at 100 Hz

IR IN and OUT

Input Resistance > 10 kohms

Input Voltage Min 5 V

Output Resistance < 30 ohms

TRIGGER Out

Output Current 50 mA

Output Voltage 12 V

DIMENSIONS AND WEIGHTS

Net Weight 6.5 kg ( 14.3 Ib)
Shipping Weight 8 kg ( 17.6 Ib)

×

DIMENSION (W×H×D) 435

100 × 290MM

WIRING DIAGRAM

8

AC POWER PLUG

AC OUTLET

T401(TRANSFORMER)

POWER SWITCH

CB45

CB47

Q215

P1-L

-46V WHITE
+46V RED

P2-L

Q214

P5-GND

Q114

P4-R

+46V RED

-46V WHITE

P3-R

Q115

MAIN BOARD

CB21

CB11

CB32

CB33

CB35

CB31

CB34

AMP-SMD-R BOARD

CZ11

AMP-SMD-L BOARD

CZ21

IN MODULE BOARD

01-32560-01

CB61

OUT MODULE BOARD

01-32560-02

CB61

CB51

CB55

POWER BOARD

CB58

CB52

CB53

CB54

CZ45

HEADPHONE BOARD

Ipod SOCKET BOARD

CZ75

CZ74

CZ72

IR BOARD

CZ73

STANDBY BOARD

CB73

CB74

S75

S74

KEY BOARD

S76

S71

S72

S73

S77

CZ72_1

CZ71

CB72

CB56

CB59

CB57

DISC L

9

DISC R

VIDEO L

VIDEO R

AUX L

AUX R

TUNER L

TUNER R

TAPE1 IN L

TAPE1 IN R

TAPE1 OUT L

TAPE1 OUT R

TAPE2 IN L

TAPE2 IN R

TAPE2 OUT L

TAPE2 OUT R

11,12,13,14)

RT31

RT32

RT34

SW31

SCR

CONTROL

CIRCUIT

TRIG I-V

ISC CIRCUIT

(IC43,TL082D)

(4,5,6,7

IC74
CD4094

BASS

TREBLE

BALANCE

TONE DEFEAT

MIRROR
CURRENT
SOURCE

CIRCUIT

R467

POSISTOR

(80 DEGREE C)

01-32560-02

(IC44,UPC1237HA)

R439

POSISTOR

(90 DEGREE C)

INPUT SELECTION

CIRCUIT (BY RELAY)

MP L

MP R

CD L

CD R

01-32560-01

IN

˄˅

AMP CIRCUIT

PREAPM MODULE

Relay Switchs

RL12/2

Speaker R

Speaker L

F1AA012V

92

IC 75
CD4094

OUT

˄˅

AMP CIRCUIT

PREAPM MODULE

MUTE

CONTROL

CIRUIT

PROTECTION

CIRCUIT

VOL+

5

4

VOL-

VOLUME CONTROL

CIRCUIT (REMOTE)

Q31

MUTE

Q32

MUTE

POWER AMP

CIRCUIT L

PRE-OUT L

PRE-OUT R

S41

SOFT CLIPPING

CONTROL CIRCUIT

RT33

VOLUME

CONTROL

BLOCK DIAGRAM

MAIN IN R

MCU

MCU

(1,2,3)

(1,3)

HEADPHONE

JK41

POWER AMP

CIRCUIT R

MAIN IN L

4

10

3

Vss

SDA5SCL6NC7Vcc

CIRCUIT

IR OUT

+5V

3

2

27pF

IC72

1

IS1U60L

C79

C710

27pF

IC71

24C01

NC1NC2NC

8

+5V

Y71

11.0592M

IR Flash

Mute Flash

Remote Mute Flash

IP
C
TA1
DI
TU
TA2
AU
VI

TO RELAY CONTROL CIRCUITTO VOL CONTROL CIRCUIT

CIRCUIT

IR IN

IC75

10

9

11
12
13
14

7
6
5
4

10

9

11
12
13
14

7
6
5
4

4094

IC74

4094

8

QS

VEE

QS

Q8
Q7
Q6

16

Q5

VCC

15

Q4

OE

+5V

3

Q3

CLK

2

Q2

D

1

Q1

STR

10

5

6

7

9

P3.48P3.5

GND

P3.3(INT1)

P3.2(INTO)

8

QS

VEE

QS

Q8
Q7
Q6

16

Q5

VCC

15

Q4

OE

+5V

3

Q3

CLK

2

Q2

D

1

Q1

STR

P3.711(AIN0)P1.012(AIN1)P1.113P1.214P1.215P1.416P1.517P1.618P1.719VCC

3

XTAL24XTAL1

Input selection

Keys

P3.0(RXD)2P3.1(TXD)

1

RST/VPP

20

IC73
AT89C4051

+5V

2

MICROPROCESSOR CONNECTION DIAGRAM

13

IC76
TCM810MEND

+5V

PHONE71
Ipod IN

Circuit

18V Power Supply

Sandby control line

10k

10k

10K

2K2

Q717

+5V

CD4094

11

KEY BOARD IC74&IC75

PIN CONFIGURATION

1

STROBE

2

DATA

3

CLK

4

Q1

5

Q2

6

Q3

7

Q4

89

VSS

16

15

14

13

12

11

10

VDD

OUTPUT ENABLE

Q5

Q6

Q7

Q8

Q'S

QS

2

CLOCK

*

3

STROBE

*

1

OUTPUT ENABLE

*

15

CL

p

Q

D

1

CL
CL

TR

CL

CL

TR

LATCH

TR

1

VDD

CL
CL

TR

3 - STSTE

1

p

4

Q1

Q

D

2

TR

DQ

CL
CL

n

8

CL

Q

CL

CL

STAGES

TR

VSS

3- 7

TR

LATCH

2

TR

3-

STATE

2

n

n

5

Q2

6

7121314

Q3 Q4 Q5 Q6 Q7

TR

LATCH

TR

8

3

STATE

8

11

Q8

p
n

SERIAL

OUT

10

Q'S

SERIAL

OUT

10

QS

*VDD

* ALLINPUTS
PROTECTED BY
CMOS PROTECTION
NETWORK

VSS

TL082D

MAIN BOARD IC41&IC42&IC43

OUTPUT A

INVERTING INPUT A

NON-INVERTING INPUT A

1

2

A

-

3

++

45

V-

8

V+

7

B

OUTPUT B

-

6

INVERTING INPUT B

NON-INVERTING INPUT B

uPC1237HA

12

MAIN BOARD: IC44

8PIN PLASTIC SLIM SIP

1

8

ICS BLOCK DIAGRAM

VCC

78

1

2

Overload Detector

Output Offset Detector

Flip--Flop

VCC ON

MUTE

AC---OFF detector

Relay driver

6

5

GND

Switch for latch/automatic --reset

43