NAD-S400-tun-sm 维修电路原理图.pdf

NADSERVICE MANUALS 400S 400RDS FM TUNERRDS FM TUNER DRAFT DATE: 10 NOV, 2003RadioFans.CN 收音机爱 好者资料库RadioFans.CN 收音机爱 好者资料库CAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN ANY WAY,NEVER PERFORM CUSTOMIZED INSTALLATIONS WITHOUT MANUFAC-TURERS APPROVAL. UNAUTHORIZED MODIFICATIONS WILL NOT ONLYVOID THE WARRANTY, BUT MAY LEAD TO YOUR BEING LIABLE FOR ANYRESULTING PROPERTY DAMAGE OR USER INJURY.SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU ARETHOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING SAFETYCHECKS AND SERVICING GUIDELINES. TO DO OTHERWISE,INCREASES THE RISK OF POTENTIAL HAZARDS AND INJURY TO THEUSER.WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR PROTEC-TION FROM A.C. LINE SHOCK.SAFETY CHECKSAFTER THE ORIGINAL SERVICE PROBLEM HAS BEEN CORRECTED. ACHECK SHOULD BE MADE OF THE FOLLOWING.SUBJECT : FIRE & SHOCK HAZARD1. BE SURE THAT ALL COMPONENTS ARE POSITIONED IN SUCH A WAYAS TO AVOID POSSIBILITY OF ADJACENT COMPONENT SHORTS.THIS IS ESPECIALLY IMPORTANT ON THOSE MODULES WHICH ARETRANSPORTED TO AND FROM THE REPAIR SHOP.2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVE DEVICESSUCH AS INSULATORS, BARRIERS, COVERS, SHIELDS, STRAIN RELIEFS, POWER SUPPLY CORDS, AND OTHER HARDWARE HAVEBEEN REINSTALLED PER ORIGINAL DESIGN. BE SURE THAT THESAFETY PURPOSE OF THE POLARIZED LINE PLUG HAS NOT BEENDEFEATED.3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLE COLDSOLDER JOINTS, SOLDER SPLASHES OR SHARP SOLDER POINTS.BE CERTAIN TO REMOVE ALL LOOSE FOREIGN PARTICLES.4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR DETERIORATIONTO PARTS AND COMPONENTS, FOR FRAYED LEADS, DAMAGEDINSULATION (INCLUDING A.C. CORD), AND REPLACE IF NECESSARY.FOLLOW ORIGINAL LAYOUT, LEAD LENGTH AND DRESS.5. NO LEAD OR COMPONENT SHOULD TOUCH A RECIVING TUBE ORA RESISTOR RATED AT 1 WATT OR MORE. LEAD TENSION AROUNDPROTRUDING METAL SURFACES MUST BE AVOIDED.6. ALL CRITICAL COMPONENTS SUCH AS FUSES, FLAMEPROOFRESISTORS, CAPACITORS, ETC. MUST BE REPLACED WITH EXACTFACTORY TYPES, DO NOT USE REPLACEMENT COMPONENTSOTHER THAN THOSE SPECIFIED OR MAKE UNRECOMMENDED CIR-CUIT MODIFICATIONS.7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM AN A.C.LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OF THE CABI-NET, (THE CHANNEL SELECTOR KNOB, ANTENNA TERMINALS. HAN-DLE AND SCREWS) TO BE SURE THE SET IS SAFE TO OPERATEWITHOUT DANGER OF ELECTRICAL SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS TEST USE AN A.C. VOLT-METER, HAVING 5000 OHMS PER VOLT OR MORE SENSITIVITY, INTHE FOLLOWING MANNER; CONNECT A 1500 OHM 10 WATT RESIS-TOR, PARALLELED BY A .15 MFD. 150.V A.C TYPE CAPACITORBETWEEN A KNOWN GOOD EARTH GROUND (WATER PIPE, CON-DUIT, ETC.) AND THE EXPOSED METALLIC PARTS, ONE AT A TIME.MEASURE THE A.C. VOLTAGE ACROSS THE COMBINATION OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR. REVERSE THE A.C. PLUGAND REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED METALLIC PART. VOLTAGE MEASURED MUST NOT EXCEED 75VOLTS R.M.S. THIS CORRESPONDS TO 0.5 MILLIAMP A.C ANYVALUE EXCEEDING THIS LIMIT CONSTITUTES A POTENTIAL SHOCKHAZARD AND MUST BE CORRECTED IMMEDIATELY.SUBJECT: GRAPHIC SYMBOLSTHE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHINAN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THESERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED“DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAG-NITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIAN-GLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TOTHE PRESENCE OF IMPORTANT SAFETY INFORMATION INSERVICE LITERATURE.SUBJECT : X-RADIATION1. BE SURE PROCEDURES AND INSTRUCTIONS TO ALL SERVICE PER-SONNEL COVER THE SUBJECT OF X-RADIATION. THE ONLY POTEN-TIAL SOURCE OF X-RAYS IN CURRENT T.V. RECEIVERS IS THE PIC-TURE TUBE. HOWEVER, THIS TUBE DOES NOT EMIT X-RAYS WHENTHE HIGH VOLTAGE IS AT THE FACTORY SPECIFIED LEVEL. THE PROPER VALUE IS GIVEN IN THE APPLICABLE SCHEMATIC. OPERA-TION AT HIGHER VOLTAGES MAY CAUSE A FAILURE OF THE PIC-TURE TUBE OR HIGH VOLTAGE SUPPLY AND, UNDER CERTAIN CIR-CUMSTANCES, MAY PRODUCE RADIATION IN EXCESS OF DESIR-ABLE LEVELS.2. ONLY FACTORY SPECIFIED C.R.T. ANODE CONNECTORS MUST BEUSED. DEGAUSSING SHIELDS ALSO SERVE AS AN X-RAY SHIELD INCOLOR SETS, ALWAYS RE-INSTALL THEM.3. IT IS ESSNTIAL THAT SERVICE PERSONNEL HAVE AVAILABLE ANACCURATE AND RELIABLE HIGH VOLTAGE METER. THE CALIBRA-TION OF THE METER SHOULD BE CHECKED PERIODICALLYAGAINST A REFERENCE STANDARD, SUCH AS THE ONE AVAILABLEAT YOUR DISTRIBUTOR.4. WHEN THE HIGH VOLTAGE CIRCUITRY IS OPERATING PROPERLYTHERE IS NO POSSIBILITY OF AN X-RADIATION PROBLEM. EVERYTIME A COLOR CHASSIS IS SERVICED. THE BRIGHTNESS SHOULDBE RUN UP AND DOWN WHILE MONITORING THE HIGH VOLTAGEWITH A METER TO BE CERTAIN THAT THE HIGH VOLTAGE DOESNOT EXCEED THE SPECIFIED VALUE AND THAT IT IS REGULATINGCORRECTLY. WE SUGGEST THAT YOU AND YOUR SERVICE ORGA-NIZATION REVIEW TEST PROCEDURES SO THAT VOLTAGE REGU-LATION IS ALWAYS CHECKED AS A STANDARD SERVICING PROCE-DURE AND THAT THE HIGH VOLTAGE READING BE RECORDED ONEACH CUSTOMERS INVOICE.5. WHEN TROUBLESHOOTING AND MAKING TEST MEASUREMENTS INA PRODUCT WITH A PROBLEM OF EXCESSIVE HIGH VOLTAGE,AVOID BEING UNNECESSARILY CLOSE TO THE PICTURE TUBE ANDTHE HIGH VOLTAGE SUPPLY. DO NOT OPERATE THE PRODUCTLONGER THAN IT IS NECESSARY TO LOCATE THE CAUSE OF EXCES-SIVE VOLTAGE.6. REFER TO HV. B+ AND SHUTDOWN ADJUSTMENT PROCEDURES DESCRIBED IN THE APPROPRIATE SCHEMATIC AND DIAGRAMS(WHERE USED).SUBJECT: IMPLOSION1. ALL DIRECT VIEWED PICTURE TUBES ARE EQUIPPED WITH AN INTE-GRAL IMPLOSION PROTECTION SYSTEM, BUT CARE SHOULD BETAKEN TO AVOID DAMAGE DURING INSTALLATION, AVOIDSCRATCHING THE TUBE. IF SCRATCHED REPLACE IT.2. USE ONLY RECOMMENDED FACTORY REPLACEMENT TUBES.SUBJECT : TIPS ON PROPER INSTALLATION1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS, CUBBY-HOLE OR CLOSELY FITTING SHELF SPACE, OVER OR CLOSE TOHEAT DUCT, OR IN THE PATH OF HEATED AIR FLOW.2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS: OUTDOOR PATIOINSTALLATIONS WHERE DEW IS A FACTOR, NEAR STEAM RADIA-TORS WHERE STEAM LEAKAGE IS A FACTOR, ETC.3. AVOID PLACEMENT WHERE DRAPERIES MAY OBSTRUCT REARVENTING. THE CUSTOMER SHOULD ALSO AVOID THE USE OF DEC-ORATIVE SCARVES OR OTHER COVERINGS WHICH MIGHTOBSTRUCT VENTILATION.4. WALL AND SHELF MOUNTED INSTALLATIONS USING A COMMER-CIAL MOUNTING KIT, MUST FOLLOW THE FACTORY APPROVED MOUNTING INSTRUCTIONS. A PRODUCT MOUNTED TO A SHELF ORPLATFORM MUST RETAIN ITS ORIGINAL FEET (OR THE EQUIVALENTTHICKNESS IN SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS THE BOTTOM. BOLTS OR SCREWS USED FOR FASTENERSMUST NOT TOUCH ANY PARTS OR WIRING. PERFORM LEAKAGETEST ON CUSTOMIZED INSTALLATIONS.5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ONSLOPING SHELF OR A TILTED POSITION, UNLESS THE PRODUCT ISPROPERLY SECURED.6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITSMOUNTING TO THE CART. CAUTION THE CUSTOMER ON THE HAZ-ARDS OF TRYING TO ROLL A CART WITH SMALL CASTERS ACROSSTHRESHOLDS OR DEEP PILE CARPETS.7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STANDWHICH 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 OFTHE SAME OR LARGER SCREEN SIZE.8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION CORDS. EXPLAIN THAT A FOREST OF EXTENSIONS SPROUTING FROM A SIN-GLE OUTLET CAN LEAD TO DISASTROUS CONSEQUENCES TOHOME AND FAMILY.PRODUCT SAFETY SERVICING GUIDELINES FOR NAD PRODUCTSA.C. VOLTMETERGOOD EARTH GROUNDSUCH AS THE WATERPIPE. CONDUIT. ETCPLACE THIS PROBEON EACH EXPOSEDMETAL PARTPreliminar y ALIGNMENT PROCEDURE FOR NAD S400: EQUIPMENT REQUIRED FOR ALIGNMENT PROCEDURE: FM RF signal generator capable of 75MHz to 109MHz output 75 that can separately modulate left and right channels (Panasonic model # VP-7637A or equivalent) DMM with a basic accuracy of better than +/- 0.05%. High impedance (10 M) dual channel audio AC voltmeter with decibel readout with accuracy of better than +/- 3%. Dual channel oscilloscope that has greater than 20MHz bandwidth. Non-Ferris tuning tools. ALIGNMENT PROCEDURE: WARNING: MOST OF THE ALIGNMENT POINTS AND ADJUSTMENTS ARE FOUND UNDER A SEALED BY SOLDER SHIELD. NORMALLY THERE SHOULD NOT BE A REASON FOR ACCESS TO THE ALIGNMENT POINTS AND ADJUSTMENTS, UNLESS PARTS HAVE BEEN REPLACED. ONLY ATTEMPT ALIGNMENT IF ALL EQUIPMENT MENTIONED ABOVE IS AVAILABLE AND ONLY IF QUALIFIED PERSONNEL PERFORM THE ALIGNMENT. Depending on the country, the S400 can be setup differently via the front panel buttons. Hold down the MODE button while switching on the power. You now see a start up menu, where you can toggle between the various menu options with the DISPLAY button and save the choice with the STORE button. For continental US select: BAND = EU-USA (87.500 MHz to 108.500 MHz) EQ = 75us AUTO STEP = 100kHz, DELETE PRESETS? = (DISPLAY button = yes, STORE button = no)? For Europe select: BAND = EU-USA (87.500 MHz to 108.500 MHz) EQ = 50us AUTO STEP = 50kHz, DELETE PRESETS? = (DISPLAY button = yes, STORE button = no)? For Japan select: BAND = JAPAN (75.500 MHz to 90.500 MHz) EQ = 75us AUTO STEP = 100kHz, DELETE PRESETS? = (DISPLAY button = yes, STORE button = no)? Alignment of RF front-end: 1) Press the IF-button to select IF NARROW. Press the ANTENNA-button and select ANTENNA 2. Then connect an RF signal generator to ANTENNA port #2 and set to: Amplitude = 45 dBu Pilot tone = off Modulation = off Frequency = 98.000 MHz. NAD S400Preliminar y 2) Tune the S400 to 108.500 MHz (90.500 MHz for Japan). Looking at the S400 from the front, measure with a DMM at the right hand side of R21 found at position “R6” on the board. Adjust L13 until the tuning voltage is 10.0V DC. 3) Tune the S400 to 98,000 MHz (83.00 MHz for Japan). Measure with an oscilloscope, the IF-signal 10.7 MHz at the common point between CF3 and CF4 found at position “O4” (see Figure 1). This point will be “DC voltage free”. Leave the oscilloscope set to this point until told to remove it. In the order listed below: Adjust L10 until the IF-signal for maximum setting. Adjust L7 until the IF-signal for maximum setting. Adjust L1 until the IF-signal for maximum setting. Readjust L10, L7 and L1 until there is no more improvement for the maximum settings. IF Measurement Point CF4CF2CF3 Figure 1 L1L2L10L12L7VR1L13IC1R21Unsolder ClipUnsolder Clip Figure 2 NAD S400Preliminar y 4) With the same oscilloscope setup as in procedure #3, press the ANTENNA button and select ANTENNA port #1. Check that the IF-signal is reduced by a minimum of 40 dB. 5) Connect the signal generator to ANTENNA port #1. With the same oscilloscope setup as in procedure #3, adjust L2 until the IF-signal is at maximum setting. Press the ANTENNA button and select ANTENNA port #2. Check that the IF-signal is reduced by a minimum of 40 dB. NOTE: Return to step #3 and perform the same alignment procedure but substitute L2 for L1. Continue to align L10, L7, L2, and L1, until there is no improvement in IF-level maximum level between the two antenna ports, and that the isolation between the two ports is greater that 40 dB. Alignment of IF Section: 6) Connect an RF signal generator to ANTENNA port #1 and set to: Amplitude = 45 dBu Pilot tone = off Modulation = off Frequency = 98.000 MHz. Press the ANTENNA-button and select ANTENNA port #1. Press the IF-button to select IF WIDE. With the same oscilloscope setup as in procedure #3, check that the IF-signal had increased approximately 3 dB compared to IF NARROW. Remove the oscilloscope probe from the common point between CF3 and CF4. 7) Connect an RF signal generator to ANTENNA port #1 and set to: Amplitude = 70 dBu Pilot tone = off Modulation = off Frequency = 98.000 MHz. Adjust L13 (or VR1) until the centre-tune LED turns on. Fine adjust VR1 so that it lights from approximately 97,965 MHz. to 98,035 MHz equally. Alignment of Audio Section: 8) Set the S400 as the following: Press the IF-button to select IF WIDE. Press the ANTENNA-button and select ANTENNA 1. Press the MONO/MUTE-button to MUTE OFF MONO. Press the BLEND-button to BLEND OFF. Press the BANDWIDTH-button to BANDWIDTH WIDE. Tune the S400 to 98.00 MHz. 9) Connect an audio AC voltmeter with decibel display to both the right and left audio output jacks. Set the AC-voltmeter to negative 30 dB range. Leave the audio AC-voltmeter attached to the S400 audio output jacks until told to remove it. Then connect an RF signal generator to ANTENNA port #1 and set to: Amplitude = 45 dBu Pilot tone = on (19 kHz 10%) Modulation = off Frequency = 98,00 MHz 10) Adjust L3 for a minimum 19 kHz output at the right audio jack. 11) Adjust L4 for a minimum 19 kHz output at the left audio jack NAD S400Preliminar y 12) With the audio AC-voltmeter connected as in procedure #9, select 0 db range for both channels. Connect an RF signal generator to ANTENNA port #1 and set to: Amplitude = 65 dBu Pilot tone = on (19 kHz 10%) Modulation = 100% (including pilot tone) 1kHz +/- 75 kHz L+R and L-R. Frequency = 98,000 MHz. 13) Set the S400 as the following: Press the IF-button to select IF WIDE. Press the ANTENNA-button and select ANTENNA 1. Press the MONO/MUTE-button to MUTE ON STEREO. Press the BLEND-button to BLEND OFF. Press the BANDWIDTH-button to BANDWIDTH WIDE. Tune the S400 to 98.00 MHz. 14) Check that the audio output is approximately 0 dB +/- 1 dB (775 mV rms) in both right and left output jacks. 1. Turn the variable capacitor C37 so that the capacitor fins do not mesh, then switch off the modulation in the right side of the RF signal generator. Adjust L12 until minimum audio output is measured in the right side. Record this minimum output level. 2. Switch on the modulation in the right side of the RF signal generator. Switch off the modulation in the left side of the RF signal generator. Adjust L12 until minimum audio output is measured in the left side. Record this minimum output level. Use the side with the worst channel separation to adjust L12, by repeating the above two steps. After adjusting L12 adjust C37 to minimum output level (maximum channel separation). Channel separation should be 45 dB (+/- 5 dB). 15) Press the IF-button to select IF NARROW. Check that the channel separation drops approximately 10 dB (+/- 5dB) at the audio output jacks. 16) Press the BLEND-button to select BLEND ON. Check that the channel separation drops to approximately 15 dB. (+/- 3 dB) at the audio output jacks. Remove the audio AC-voltmeter from the audio output jacks, as well as the RF signal generator form the antenna port. 17) Set the S400 to default settings for the tuner as the following: Press the IF-button to select IF WIDE. Press the ANTENNA-button and select ANTENNA 1. Press the MONO/MUTE-button to MUTE ON STEREO. Press the BLEND-button to BLEND OFF. Press the BANDWIDTH-button to BANDWIDTH WIDE. After 10 sec. the settings will be stored. NAD S400Preliminar y L1L2L10L12L7VR1L13IC1R21UnsolderClipUnsolder ClipCF4CF2CF3L14C37L3L4RIGHTLEFTANTENNA 2ANTENNA 1 NAD S400Preliminar yNAD S400Preliminar yNAD S400Preliminar yNAD S400Preliminar yNAD S400Preliminar yNAD S400Preliminar yNA