Nad C-445 Service Manual
NAD
SERVICE MANUAL
C 445
CFM / AM
C 445
FM / AM
DAB TUNER
DAB TUNER
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 INST ALLATION
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.
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SPECIFICATIONS
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FM SECTION
Frequency Range: 87.50 MHz to 108.00 MHz
(50 kHz steps)
Signal-to-Noise Ratio: 65dB (Mono) 60dB (Stereo)
Presets: 30
AM SECTION
Frequency Range: 522 kHz to 1620 kHz (9 kHz steps)
Signal-to-Noise Ratio: 35dB
Presets:
DAB SECTION
Band lll: 174MHz - 240MHz
Band L : 1452MHz - 1492MHz
Max signal: ~ -3dBm
Sensitivity: -96dBm
Adjacent Channel Rejection: ~ 35dB
Presets:
30
~
99
Display: 2-line by 16-character DOT Matrix
Audio Output Stereo: 2.5V P-P
48kHz sample rate, 16 bit sample resolution
Optical S/PDIF: IEC60958 Compliant.
48kHz sample rate, 24 bit sample resolution
GENERAL
Power Requirement: 230-240V AC, 50Hz
Power Consumption: 12W 0.8W(standby)
DIMENSIONS (MAX)
Width Height Depth: 435 x 86 x 318mm
Weight:
6kg
TROUBLESHOOTING
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This unit is designed for trouble-free operation. Most problems users encounter are due to operating errors. If you have a problem, first check this list
for a possible solution. If the problem persists, consult your authorized Service Centre.
Symptom Cause/Correction
No lights appear when System Power button is pressed Unit is plugged into a live outlet.
No sound is heard Tune to an active station.
Sound distorts, particularly in stereo mode. Use a more directional antenna.
Intermittent or continuous buzzing or hissing Place the unit further away from these appliances.
Display says 'No stations Available' Check that antenna is connected.
Display has gone blank or says 'service off air' This may occur if a broadcaster changes the label of a service or removes a label
Unit's operation or the displays seem abnormal To correct this problem, first unplug the unit from the AC wall outlet and wait at
Make sure the outlet is active.
Check for correct amplifier settings.
Check the connections and wires.
Install noise filters on the appliances.
Ensure that DAB coverage exists in your area.
whilst you are listening to it. Try to retune to this station, using the Autotune
procedure.
least three minutes. After the pause, reconnect the AC power cord and check the
unit's operation.
Reset the C445 Tuner; press and hold the Menu/FM Mute Button for 5 seconds,
until the Information Display shows FACTORY RESET. Note that when the system
is reset, all tuner presets will be lost and must be re-entered.
Press the RESET switch lightly once or twice with a pencil or ballpoint pen as per
example below.
If these steps do not solve the problem, consult your dealer or an authorized
service centre.
Rear Panel
MAINTENANCE FLOW CHART
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Start
Power on
Voltages NO 1. Check Cable
at pins of connector 2. Replace Power Supply unit if Power Board is not shorted,
(CN93) are normal? otherwise find out first where the short is.
YES
NO NO Check CNVMB114MA18L
Are FM/AM Is Power Supply (Tuner Module)
MAIN Board normal? normal? and peripheral circuit.
(CUP11866Y)
YES
NO
Is PLL Check S3F84BB
Clock normal? and peripheral circuit.
YES YES
Chcek TUNER module connection Antenna.
Power Board
(CUP11866Y)
NO NO Check DAB Module
Is DAB Is Power Supply and peripheral
normal? normal? circuit.
YES
NO Check 74ACT04(IC73) or
Is Voltage level 74LVC04(IC74) and
normal? peripheral circuit.
MAIN Board YES
(CUP11866Y)
YES NO Check S3F84BB or DAB
Are Clock and Module and peripheral
Data normal? Circuit.
YES
Check DAB Module connection Antenna.
Normal Operation
WIRING DIAGRAM
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