NAD-T747-avr-sm(1) 维修电路原理图.pdf

L A U N A M E C I V R E S AV Surround Sound ReceiverT747AV Surround Sound ReceiverT747RadioFans.CN 收音机爱 好者资料库1-2SECTION 1SUMMARYCONTENTSPRODUCT SAFETY SERVICING GUIDELINES. 1-3SERVICING PRECAUTIONS . 1-4* General Servicing Precautions* Insulation checking prodedure* Electrostatically Sensitive DevicesSPECIFICATIONS . 1-5DISASSEMBLY . 1-6PRINCIPAL PART LOCATION. 1-7. 1-8EXPLODED VIEW .RadioFans.CN 收音机爱 好者资料库1-3PRODUCT SAFETY SERVICING GUIDELINES CAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT INANY WAY. NEVER PERFORM CUSTOMIZED INSTALLATIONSWITHOUT MANUFACTURER S APPROVAL. UNAUTHORIZEDMODIFICATIONS WILL NOT ONLY VOID THE WARRANTY, BUTMAY LEAD TO YOUR BEING LIABLE FOR ANY RESULTINGPROPERTY DAMAGE OR USER INJ URY.SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOUARE THOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWINGSAFETY CHECKS AND SERVICING GUIDELINES. TO DOOTHERWISE, INCREASES THE RISK OF POTENTIAL HAZARDSAND INJ URY TO THE USER. WHILE SERVICING, USE AN ISOLATION TRANSFORMER FORPROTECTION FROM AC LINE SHOCK.SAFETY CHECKSAFTER THE ORIGINAL SERVICE PROBLEM HAS BEENCORRECTED. A CHECK SHOULD BE MADE OF THEFOLLOWING.SUBJECT : FIRE & SHOCK HAZARD1. BE SURE THAT ALL COMPONENTS ARE POSITIONED INSUCH A WAY AS TO AVOID POSSIBILITY OF ADJACENTCOMPONENT SHORTS. THIS IS ESPECIALLY IMPORTANTON THOSE MODULES WHICH ARE TRANSPORTED TO ANDFROM THE REPAIR SHOP. 2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVEDEVICES SUCH AS INSULATORS, BARRIERS, COVERS,SHIELDS, STRAIN RELIEFS, POWER SUPPLY CORDS, ANDOTHER HARDWARE HAVE BEEN REINSTALLED PERORIGINAL DESIGN. BE SURE THAT THE SAFETY PURPOSEOF THE POLARIZED LINE PLUG HAS NOT BEEN DEFEATED.3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLECOLD SOLDER JOINTS, SOLDER SPLASHES OR SHARPSOLDER POINTS. BE CERTAIN TO REMOVE ALL LOOSEFOREIGN PARTICLES.4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE ORDETERIORATION TO PARTS AND COMPONENTS. FORFRAYED LEADS, DAMAGED INSULATION (INCLUDING ACCORD). AND REPLACE IF NECESSARY FOLLOW ORIGINALLAYOUT, LEAD LENGTH AND DRESS.5. NO LEAD OR COMPONENT SHOULD TOUCH A RECEIVINGTUBE OR A RESISTOR RATED AT 1 WATT OR MORE. LEADTENSION AROUND PROTRUDING METAL SURFACES MUSTBE AVOIDED.6. ALL CRITICAL COMPONENTS SUCH AS FUSES,FLAMEPROOF RESISTORS, CAPACITORS, ETC. MUST BEREPLACED WITH EXACT FACTORY TYPES, DO NOT USEREPLACEMENT COMPONENTS OTHER THAN THOSESPECIFIED OR MAKE UNRECOMMENDED CIRCUITMODIFICATIONS.7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM ANAC LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OFTHE CABINET, (THE CHANNEL SELECTOR KNOB, ANTENNATERMINALS. HANDLE AND SCREWS) TO BE SURE THE SETIS SAFET TO OPERATE WITHOUT DANGER OF ELECTRICALSHOCK. DO NOT USE A LINE ISOLATION TRANSFORMERDURING THIS TEST USE AN AC VOLTMETER, HAVING 5000OHMS PER VOLT OR MORE SENSITIVITY, IN THEFOLLOWING MANNER; CONNECT A 1500 OHM 10 WATTRESISTOR, PARALLELED BY A .15 MFD, 150V AC TYPECAPACITOR BETWEEN A KNOWN GOOD EARTH GROUND(WATER PIPE, CONDUIT, ETC.) AND THE EXPOSEDMETALLIC PARTS, ONE AT A TIME. MEASURE THE AC VOLTAGE ACROSS THE COMBINATIONOF 1500 OHM RESISTOR AND .15 MFD CAPACITOR. REVERSE THE AC PLUG AND REPEAT AC VOLTAGEMEASUREMENTS FOR EACH EXPOSED METALLIC PART. VOLTAGE MEASURE MUST NOT EXCEED 75 VOLTS R.M.S.THIS CORRESPONDS TO 0.5 MILLIAMP AC ANY VALUEEXCEEDING THIS LIMIT CONSTITUTES A POTENTIALSHOCK HAZARD AND MUST BE CORRECTED IMMEDIATELY.SUBJECT : GRAPHIC SYMBOLSSUBJECT : TIPS ON PROPER INSTALLATION1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS,CUBBYHOLE OR CLOSELY FITTING SHELF SPACE. OVEROR CLOSE TO HEAT DUCT, OR IN THE PATH OF HEATEDAIR FLOW.2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS:OUTDOOR PATIO INSTALLATIONS WHERE DEW IS AFACTOR, NEAR STEAM RADIATORS WHERE STEAMLEAKAGE IS A FACTOR, ETC.3. AVOID PLACEMENT WHERE DRAPERIES MAY OBSTRUCTREAR VENTING. THE CUSTOMER SHOULD ALSO AVOID THEUSE OF DECORATIVE SCARVES OR OTHER COVERINGSWHICH MIGHT OBSTRUCT VENTILATION.4. WALL AND SHELF MOUNTED INSTALLATIONS USING ACOMMERCAL MOUNTING KIT MUST FOLLOW THE FACTORYAPPROVED MOUNTING INSTRUCTIONS A PRODUCTMOUNTED TO A SHELF OR PLATFORM MUST RETAIN ITSORIGINAL FEET (OR THE EQUIVALENT THICKNESS INSPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSSTHE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERSMUST NOT TOUCH ANY PARTS OR WIRING. PERFORMLEAKAGE TEST ON CUSTOMIZED INSTALLATIONS.5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF APRODUCT ON SLOPING SHELF OR A TILTED POSITION,UNLESS THE PRODUCT IS PROPERLY SECURED.6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLEON ITS MOUNTING TO THE CART. CAUTION THECUSTOMER ON THE HAZARDS OF TRYING TO ROLL A CARTWITH SMALL CASTERS ACROSS THRESHOLDS OR DEEPPILE CARPETS.7. CAUTION CUSTOMERS AGAINST THE USE OF A CART ORSTAND WHICH HAS NOT BEEN LISTED BY UNDERWRITERSLABORATORIES, INC. FOR USE WITH THEIR SPECIFICMODEL OF TELEVISION RECEIVER OR GENERICALLYAPPROVED FOR USE WITH T.V. S OF THE SAME ORLARGER SCREEN SIZE.8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSIONCORDS, EXPLAIN THAT A FOREST OF EXTENSIONSSPROUTING FROM A SINGLE OUTLET CAN LEAD TODISASTROUS CONSEQUENCES TO HOME AND FAMILY.THE LIGHTNING FLASH WITH ARROWHEAD SYMBOL, WITHIN ANEQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE USER TO THEPRESENCE OF UNINSULATED “DANGEROUS VOLTAGE” WITHIN THEPRODUCT S ENCLOSURE THAT MAY BE OF SUFFICIENT MAGNITUDE TOCONSTITUTE A RISK OF ELECTRIC SHOCK.THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE ISINTENDED TO ALERT THE USER TO THE PRESENCE OF IMPORTANTOPERATING AND MAINTENANCE (SERVICING) INSTRUCTIONS IN THELITERATURE ACCOMPANYING THE APPLIANCE.1-4SERVICING PRECAUTIONSCAUTION : Before servicing the A/V Receiver covered by thisservice data and its supplements and addends, read and follow theSAFETY PRECAUTIONS. NOTE : if unforeseen circumstancescreate conflict between the following servicing precautions and anyof the safety precautions in this publication, always follow the safetyprecautions.Remember Safety First:General Servicing Precautions1. Always unplug the A/V Receiver AC power cord from the ACpower source before:(1) Removing or reinstalling any component, circuit board,module, or any other assembly.(2) Disconnecting or reconnecting any internal electrical plug orother electrical connection.(3) Connecting a test substitute in parallel with an electrolyticcapacitor.Caution : A wrong part substitution or incorrect polarity installationof electrolytic capacitors may result in an ex plosion haz ard.2. Do not spray chemicals on or near this A/V Receiver or any of itsassemblies.3. Unless specified otherwise in this service data, clean electricalcontacts by applying an appropriate contact cleaning solution tothe contacts with a pipe cleaner, cottontipped swab, orcomparable soft applicator.Unless specified otherwise in this service data, lubrication ofcontacts is not required.4. Do not defeat any plug/socket B+ voltage interlocks with whichinstruments covered by this service manual might be equipped.5. Do not apply AC power to this A/V Receiver and/or any of itselectrical assemblies unless all solid-state device heat sinks arecorrectly installed.6. Always connect test instrument ground lead to the appropriateground before connecting the test instrument positive lead. Alwaysremove the test instrument ground lead last.Insulation Checking ProcedureDisconnect the attachment plug from the AC outlet and turn thepower on. Connect an insulation resistance meter(500V) to theblades of the attachment plug. The insulation resistance betweeneach 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, Inputterminals, Earphone jacks, etc.Electrostatically Sensitive (ES) DevicesSome semiconductor (solid state) devices can be damaged easily bystatic electricity. Such components commonly are calledElectrostatically Sensitive (ES) Devices. Ex amples of typical Esdevices are integrated circuits and some field effect transistors andsemiconductor chip components.The following techniques should be used to help reduce theincidence of component damage caused by static electricity.1. Immediately before handling any semiconductor component orsemiconductor-equipped assembly, drain off any electrostaticcharge on your body by touching a known earth ground.Alternatively, obtain and wear a commercially availabledischarging wrist strap device, which should be removed forpotential shock reasons prior to applying power to the unit undertest.2. After removing an electrical assembly equipped with ES devices,place the assembly on a conductive surface such as aluminumfoil, to prevent electrostatic charge buildup or ex posure of theassembly.3. Use only a grounded-tip soldering iron to solder or unsolder ESdevices.4. Use only an antistatic solder removal device. Some solderremoval devices not classified a “anti-static” can generateelectrical charges sufficient to damage ES devices.5. Do not use freonpropelled chemicals. These can generateelectrical charge sufficient to damage ES devices.6. Do not remove a replacement ES device from its protectivepackage until immediately before you are ready to install it. (Mostreplacement ES devices are packaged with leads electricallyshorted together by conductive foam, aluminum foil, orcomparable conductive material).7. lmmediately before removing the protective material from theleads of a replacement ES device, touch the protective material tothe chassis or circuit assembly into which the device will beinstalled.Caution : Be sure no power is applied to the chassis or circuit, andobserve all other safety precautions.8. Minimiz e bodily motions when handing unpackaged replacementES devices. (Normally harmless motion such as the brushingtogether of your clothes fabric or the lifting of your foot from acarpeted floor can generate static electricity sufficient to damagean ES device.)?SPECIFICATIONS1-51-6 DISASSEMBLY1 REMOVAL OF TOP COVER2 REMOVAL OF FRONT PANEL1-7PRINCIPAL PARTS LOCATIONT747AH EXPLODED VIEW PARTS LIST (Graphite)1-8NOTE *AMP ASSEMBLY #31 & CHASSIS #19ARE SOLD TOGETHERFASCIA ASSEMBLY #1, #3, & #4ARE SOLD TOGETHER BUTTONT747AH EXPLODED VIEW (Graphite)1-91-10SEE NOTE*SEE NOTE*SEE NOTE*T747C EXPLODED VIEW PARTS LIST (Graphite)1-11NOTE *AMP ASSEMBLY #31 & CHASSIS #19ARE SOLD TOGETHERFASCIA ASSEMBLY #1, #3, & #4ARE SOLD TOGETHER BUTTONT747C EXPLODED VIEW ( Gr aphite)1-121-13SEE NOTE*SEE NOTE*SEE NOTE*T747CT EXPLODED VIEW PARTS LIST (Titanium)1-14NOTE *AMP ASSEMBLY #31 & CHASSIS #19ARE SOLD TOGETHERFASCIA ASSEMBLY #1, #3, & #4ARE SOLD TOGETHER BUTTONT747CT EXPLODED VIEW (Titanium)1-151-16SEE NOTE*SEE NOTE*SEE NOTE*2-1SECTION 2ELECTRICAL CONTENTSCONTENTSIC BLOCK DIAGRAMS & PIN DESCRIPTION . 2-2DIAGRAM. 2-311. BLOCK DIAGRAM . 2-312. WIRING DIAGRAM . 2-393. SCHEMATIC DIAGRAM . 2-41FRONT PART . 2-41POWER PART. 2-43MCU PART. 2-45DSP&CODEC WITH DIR PART. . 2-47INPUT&VOLUME PART. 2-49XM&TUNER PART. 2-51VIDEO PART. 2-53HDMI PART. . 2-55AMP PART. . 2-634. PRINTED CIRCUIT BOARDS . 2-67FRONT . 2-67MAIN. 2-71INPUT. . 2-73VIDEO . 2-77HDMI. 2-79AMP. 2-815. TROUBLESHOOTING. 2-85 6. SPECIAL FUNCTION KEYS . 2-89?IC BLOCK DIAGRAMS & PIN DESCRIPTION2-2?2-32-4IC201:T5CC1: Micr ocontr oller s2-4 64GND_IO63CLKIN_B62S761S660S559S458S357DGND56VDD55S254S153S052TEST551TEST450S_HSYNC49S_VSYNC47RSET146VREF45COMP142DAC 343DAC 244DAC 148SFL/MISO41VAA40AGND39DAC 437DAC 636RSET235COMP234PVDD33EXT_LF138DAC 52TEST03TEST14Y07Y36Y25Y11VDD_IO8Y49Y510VDD12Y613Y714TEST215TEST316C011DGND17C118C219ALSB/SPI_SS2 0SDA/SCLK21SCL/MOSI22 2 3P_HSYNC24P_VSYNC25P_BLANK2 6C4C327C52 8C629C730CLKIN_A3132PGNDPIN 1ADV7342/ADV7343TOP VIEW( Not to Scale)EXT_LF2 Pin No. Mnemonic Input/ Output Description 13, 12, 9 to 4 Y7 to Y0 I 8-Bit Pixel Port. Y0 is the LSB. Refer to Table 31 for input modes. 29 to 25, 18 to 16 C7 to C0 I 8-Bit Pixel Port. C0 is the LSB. Refer to Table 31 for input modes. 62 to 58, 55 to 53 S7 to S0 I 8-Bit Pixel Port. S0 is the LSB. Refer to Table 31 for input modes. 52, 51, 15, 14, 3, 2 TEST5 to TEST0 I Unused. These pins should be connected to DGND. 30 CLKIN_A I Pixel Clock Input for HD Only (74.25 MHz), ED1 Only (27 MHz or 54 MHz) or SD Only (27 MHz). 63 CLKIN_B I Pixel Clock Input for Dual Modes Only. Requires a 27 MHz reference clock for ED operation or a 74.25 MHz reference clock for HD operation. 50 S_HSYNC I/O SD Horizontal Synchronization Signal. This pin can also be configured to output an SD, ED, or HD horizontal synchronization signal. See the External Horizontal and Vertical Synchronization Control section. 49 S_VSYNC I/O SD Vertical Synchronization Signal. This pin can also be configured to output an SD, ED, or HD vertical synchronization signal. See the External Horizontal and Vertical Synchronization Control section. 22 P_HSYNC I ED/HD Horizontal Synchronization Signal. See the External Horizontal and Vertical Synchronization Control section. 23 P_VSYNC I ED/HD Vertical Synchronization Signal. See the External Horizontal and Vertical Synchronization Control section. 24 P_BLANK I ED/HD Blanking Signal. See the External Horizontal and Vertical Synchronization Control section. 48 SFL/MISO I/O Multifunctional Pin: Subcarrier Frequency Lock (SFL) Input/SPI Data Output. The SFL input is used to drive the color subcarrier DDS system, timing reset, or subcarrier reset. 47 RSET1 I This pin is used to control the amplitudes of the DAC 1, DAC 2, and DAC 3 outputs. For full-drive operation (for example, into a 37.5 load), a 510 resistor must be connected from RSET1 to AGND. For low drive operation (for example, into a 300 load), a 4.12 k resistor must be connected from RSET1 to AGND. IC PIN DESCRIPTION ( IC158: ADV7342: VIDEO ENCODER)2-5 Pin No. Mnemonic Input/ Output Description 36 RSET2 I This pin is used to control the amplitudes of the DAC 4, DAC 5, and DAC 6 outputs. A 4.12 k resistor must be connected from RSET2 to AGND. 45, 35 COMP1, COMP2 O Compensation Pins. Connect a 2.2 nF capacitor from both COMP pins to VAA. 44, 43, 42 DAC 1, DAC 2, DAC 3 O DAC Outputs. Full and low drive capable DACs. 39, 38, 37 DAC 4, DAC 5, DAC 6 O DAC Outputs. Low drive only capable DACs. 21 SCL/MOSI I Multifunctional Pin: I2C Clock Input/SPI Data Input. 20 SDA/SCLK I/O Multifunctional Pin: I2C Data Input/Output. Also, SPI clock input. 19 ALSB/SPI_SS I Multifunctional Pin: This signal sets up the LSB2 of the MPU I2C address. Also, SPI slave select. 46 VREF Optional External Voltage Reference Input for DACs or Voltage Reference Output. 41 VAA P Analog Power Supply (3.3 V). 10, 56 VDD P Digital Power Supply (1.8 V). For dual-supply configurations, VDD can be connected to other 1.8 V supplies through a ferrite bead or suitable filtering. 1 VDD_IO P Input/Output Digital Power Supply (3.3 V). 34 PVDD P PLL Power Supply (1.8 V). For dual-supply configurations, PVDD can be connected to other 1.8 V supplies through a ferrite bead or suitable filtering. 33 EXT_LF1 I External Loop Filter for On-Chip PLL 1. 31 EXT_LF2 I External Loop Filter for On-Chip PLL 2. 32 PGND G PLL Ground Pin. 40 AGND G Analog Ground Pin. 11, 57 DGND G Digital Ground Pin. 64 GND