Nad M-4 Service Manual
SERVICE MANUAL
M4 C/AH
STEREO
M4 C/AH
STEREO
FM/AM/DAB/XM TUNER
FM/AM/DAB/XM TUNER
CONTENTS
SECTION 1 . . . .SUMMARY
SECTION 2 . . . .CABINET & MAIN CHASSIS
SECTION 3 . . . .ELECTRICAL
SECTION 4 . . . .REPLACEMENT PARTS LIST
SECTION 1
SUMMARY
CONTENTS
PRODUCT SAFETY SERVICING GUIDELINES FOR AUDIO PRODUCTS
SERVICING PRECAUTIONS ...........................................................................1-3
• General Servicing Precautions
• Insulation Checking Prodedure
• Electrostatically Sensitive Devices
SPECIFICATIONS ........................................................................................... 1-4,5
............. 1-2
1-1
PRODUCT SAFETY SERVICING GUIDELINES FOR AUDIO PRODUCTS
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 A.C. LINESHOCK.
SAFETY CHECKS
AFTER THE ORIGINAL SERVICE PROBLEM HAS
BEEN CORRCTED. A CHECK SHOULD BE MADE OF
THE FOLLOWING.
SUBJECT : FIRE & SHOCK HAZARD
1.BE SURE THAT ALL COMPONENTS ARE POSI-
TIONED 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 HAVEBEEN 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 A.C. CORD). AND REPLACE IF NECES-
5. NO LEAD OR COMPONENT SHOULD TOUCH A
RECIVING TUBE OR A RESISTOR RATED AT 1 WATT
OR MORE. LEAD TENSION AROUND PROTRUNING
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 A.C. 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 SAFE TO
OPERATE WITHOUT DANGER OF ELECTRICAL
SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS TEST USE AN A.C. 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. 150.V A.C TYPE CAPACITOR BETWEEN A
KNOWN GOOD EARTH GROUND (WATER PIPE,
CONDUIT,ETC.) AND THE EXPOSED METALLIC
PARTS, ONE AT A TIME. MEASURE THE A.C. VOLTAGE ACROSS THE COMBINATION OF 1500OHM
RESISTOR AND .15 MFD CAPACITOR. REVERSE THE
A.C. PLUG AND REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED METALLIC PART. VOLTAGE MEASURED MUST NOT EXCEED 75 VOLTS
R.M.S. THIS CORRESPONDS TO 0.5 MILLIAMP A.C
ANY VALUE EXCEEDING THIS LIMIT CONSTITUTES A
POTENTIAL SHOCK HAZARD AND MUST BE CORRECTED IMMEDIATELY.
A.C. VOLTMETER
GOOD EARTH GROUND
SUCH AS THE WATER
PIPE. CONDUIT. ETC
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
SUBJECT: GRAPHIC SYMBOLS
THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED
TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED “DANGEROUS VOLTAGE”
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 SERVICE
PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE.
1-2
SERVICING PRECAUTIONS
CAUTION
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 Stereo Tuner AC power cord from the AC
power source before:
(1) Removing or reinstalling any component, circuit board,
(2) Disconnecting or reconnecting any internal electrical
(3) Connecting a test substitute in parallel with an electrolytic
Caution: A wrong part substitute or incorrect polarity
2. Do not spray chemicals on or near this Stereo Tuner 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 Stereo Tuner 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 1 M-ohm.
Note 1: Accessible Conductive Parts including Metal panels,
Input terminals, Earphone jacks, etc.
: Before servicing the Stereo Tuner covered by
module, or any other assembly.
plug or other electrical connection.
capacitor.
installation of electrolytic capacitors may result in an
explosion hazard.
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 handing 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 reason 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. Immediately 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.)
1-3
SPECIFICATIONS
AM TUNER SECTION
Usable Sensitivity (999/1000kHz) 30dBμ
S/N Ratio (5mV in) 38dB
THD (5mV in) <3%
IF Rejection (450kHz) >36dB
Image Rejection (F+2xIF) 28dB
Selectivity 17dB
Output 130mV ±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
Usable Sensitivity (98 MHz) 6 dBμ
Signal / Noise Ratio Mono 72 dB
(60 dBμ, IHF wtd) Stereo >66 dB
Frequency Response
(20 Hz - 15 kHz, 60 dBμ) ±1.0 dB
Channel Separation (60 dBμ)
30 Hz >33 dB
1 kHz >42 dB
10 kHz >35 dB
Alternate Channel Sensitivity
(40 dBμ, ±400 kHz) 60 dB
Capture Ratio (40 dBμ) 1.5 dB
AM Suppression
(60 dBμ, 100% Mod.FM, 30% Mod.AM) 65 dB
Image Rejection (119.4 MHz) 85 dB
I.F. Rejection (10.7 MHz) 80 dB
Pilot Suppression (60 dBμ) 60 dB
THD (60 dBμ, L=R 75 kHz for North America version; 40 kHz
deviation for Europe version)
1-4
Mono 0.20%
Stereo 0.25%
Auto-Search
Sensitivity On 24dBμ
Sensitivity Off 15 dBμ
RDS Decode Sensitivity 25 dBμ
DAB SECTION
Band lll 174MHz-240MHz
Input 50 Ohm, nominal
Max signal ~ -3dBm
Sensitivity ~ -96dBm
Adjacent Channel Rejection ~ 35dB
Display 2-line by 16-character
DOT Matrix
Audio Output Stereo 2.5Vp-p
48kHz sample rate 16 bit sample Resolution
Optical S/PDIF IEC60958 Compliant
48kHz sample rate 24 bit sample resolution
1-5
SECTION 2
CABINET & MAIN CHASSIS
CONTENTS
EXPLODED VIEWS.................................................................................. 2-2
1. Cabinet and main frame section...................................................................
2. Packing accessory section . . . .. ........................................................................ 2-3
3. Exploded view parts list.. .. . .. .. ........................................................................ 2-4
2-2
2-1
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M4 EXPLODED VIEWS
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2-2
M4 Packing Accessory Section
Batteries
REMOCON
DAB Antenna
Accessory Box
AC Cord
AM Antenna
Polyfoam(up)
polyfoam(down)
Gift Box
Shipping Box
2-3
M4 EXPLODED VIEW PARTS LIST
REF.NO. PART NO. DESCRIPTION Qty. REF.NO. PART NO. DESCRIPTION Qty.
C002 01-50404-10 XM BOARD(AH) 1
01-50403-20
C003 01-54245-20 C425 Main Board(AH Version) 1 S001 61-023206-1 Self Taping Screw (BTB3X6) 13
01-54245-10 C425 Main Board(C Version) 1 S002 61-022506-6 Machine Screw (MB2.5X6-Ni) 2
C004 01-50401-10 MAIN BOARD(AH Version) 1 S003 61-023616-0 Self Taping Screw(TBBT3×16) 4
01-50401-20 MAIN BOARD(C Version) 1 S004 61-224512-1 Hex Head Screw (M4X12) 8
C005 A18-50420-00 R Type Transformer 1 S005 61-224508-1 Hex Head Screw (M4X8) 8
C006 A18-50407-00 standby Transformer 1 S006 61-063106-0 Self Taping Screw (STF3X6) 4
C007 83-043001-0 Foot Assembly 4 S007 61-023106-2 Self Taping Screw (STB3X6) 15
F003 76-048010-0
F005 87-048002-0 Input Button Pad 7 S013 61-024106-0 Self Taping Screw (STB4×6) 2
F006 87-048003-0 Power Button Pad 2 S014 61-023508-0 Machine Screw (MB3X8) 4
F007 86-046001-0 Led Lens Gum 1 S015 63-020308-1 Spring Washer 4
F009 70-048013-0 Power Button 1
F010
F012 70-051007-0 Enter Button 1
F015 86-046002-0
F017 86-010004-0 3mm Rubber Pad 3
92-048001-0 Spring for Button 9
DAB BOARD includes DB1 ( C ) 1
S008 61-024108-1 Self Taping Screw (STB4X8) 4
S009 61-373506-0 Machine Screw (MB3X6W.S-Ni) 8
VFD window 1 S012 61-023208-0 Self Taping Screw (BTB3X8) C:9
7nottuB tupnI1-210840-07110F
1draoB PPF00-20405-10310F
11aicsaF0-200470-07J410F
Fascia Padding 2
1aicsafbuS0-300470-76610F
1tekcarB RI0-200840-6610PF1sissahC2-100470-76100C
2)iN-6X3BTS( wercS gnipaT fleS1-601320-16010S12aicsaF0-100470-07100F
4)rC-8X6BM( wercS enihcaM0-805642-16110S1rosruC gniR0-200150-07200F
6:HA1redloH rosruC1-100470-77400F
4)3M(tuN2-203010-26610S1 sneL deL0-100800-67800F
R001 67-074002-1 Rear Panel (C Version) 1
67-074004-1 Rear Panel (AH Version) 1
R002 11-01101-03 Rocker Switch 1
T003 76-046001-0 Screw Washer 4
XD01 66-083003-0 PCB Left Bracket 1
XD02 66-083004-0 PCB Right Bracket 1
1revoC poT0-200150-76100T
2x2/1daP RC0-510910-98200T
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