Zenith-XBV441-dvd-sm 维修电路原理图.pdf

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1、CONTENTSSECTION 1 . . . . SUMMARYSECTION 2 . . . . CABINET & MAIN CHASSISSECTION 3 . . . . ELECTRICALSECTION 4 . . . . MECHANISM OF VCR PARTSECTION 5 . . . . MECHANISM OF DVD PARTSECTION 6 . . . . REPLACEMENT PARTS LISTRadioFans.CN 收音机爱 好者资料库1-2SECTION 1SUMMARYCONTENTSPRODUCT SAFETY SERVICING GUIDEL

2、INES FOR VIDEO PRODUCTS. 1-3SERVICING PRECAUTIONS. 1-4 General Servicing Precautions Insulation Checking Prodedure Electrostatically Sensitive DevicesSPECIFICATIONS. 1-5RadioFans.CN 收音机爱 好者资料库1-3IMPORTANT SAFETY NOTICEThis manual was prepared for use only by properly trained audio-video servicetechn

3、icians.When servicing this product, under no circumstances should the originaldesign be modified or altered without permission from Zenith ElectronicsCorporation. All components should be replaced only with types identical tothose in the original circuit and their physical location, wiring and lead

4、dressmust conform to original layout upon completion of repairs.Special components are also used to prevent x-radiation, shock and fire haz-ard. These components are indicated by the letter “x” included in their compo-nent designators and are required to maintain safe performance. No deviationsare a

5、llowed without prior approval by Zenith Electronics Corporation.Circuit diagrams may occasionally differ from the actual circuit used. This way,implementation of the latest safety and performance improvement changesinto the set is not delayed until the new service literature is printed.CAUTION: Do n

6、ot attempt to modify this product in any way. Never performcustomized installations without manufacturers approval. Unauthorized modi-fications will not only void the warranty, but may lead to property damage oruser injury.Service work should be performed only after you are thoroughly familiar witht

7、hese safety checks and servicing guidelines.GRAPHIC SYMBOLSThe exclamation point within an equilateral triangle is intended toalert the service personnel to important safety information in theservice literature.The lightning flash with arrowhead symbol within an equilateral tri-angle is intended to

8、alert the service personnel to the presence ofnoninsulated “dangerous voltage” that may be of sufficient magni-tude to constitute a risk of electric shock.The pictorial representation of a fuse and its rating within an equi-lateral triangle is intended to convey to the service personnel thefollowing

9、 fuse replacement caution notice: CAUTION: FOR CONTINUED PROTECTION AGAINST RISKOF FIRE, REPLACE ALL FUSES WITH THE SAME TYPE ANDRATING AS MARKED NEAR EACH FUSE.SERVICE INFORMATIONWhile servicing, use an isolation transformer for protection from AC line shock.After the original service problem has b

10、een corrected, make a check of the fol-lowing:FIRE AND SHOCK HAZARD1. Be sure that all components are positioned to avoid a possibility of adjacentcomponent shorts. This is especially important on items trans-ported to andfrom the repair shop.2. Verify that all protective devices such as insulators,

11、 barriers, covers, shields,strain reliefs, power supply cords, and other hardware have been reinstalledper the original design. Be sure that the safety purpose of the polarized lineplug has not been defeated.3. Soldering must be inspected to discover possible cold solder joints, soldersplashes, or s

12、harp solder points. Be certain to remove all loose foreign par-ticles.4. Check for physical evidence of damage or deterioration to parts and compo-nents, for frayed leads or damaged insulation (including the AC cord), andreplace if necessary.5. No lead or component should touch a high current device

13、 or a resistor ratedat 1 watt or more. Lead tension around protruding metal surfaces must beavoided.6. After reassembly of the set, always perform an AC leakage test on allexposed metallic parts of the cabinet (the channel selector knobs, antennaterminals, handle and screws) to be sure that set is s

14、afe to operate withoutdanger of electrical shock. DO NOT USE A LINE ISOLATION TRANS-FORMER DURING THIS TEST. Use an AC voltmeter having 5000 ohms pervolt or more sensitivity in the following manner: Connect a 1500 ohm, 10watt resistor, paralleled by a .15 mfd 150V AC type capacitor between aknown go

15、od earth ground water pipe, conduit, etc.) and the exposed metal-lic parts, one at a time. Measure the AC voltage across the combination of1500 ohm resistor and .15 mfd capacitor. Reverse the AC plug by using anon-polarized adaptor and repeat AC voltage measurements for eachexposed metallic part. Vo

16、ltage measured must not exceed 0.75 volts RMS.This corresponds to 0.5 milliamp AC. Any value exceeding this limit consti-tutes a potential shock hazard and must be corrected immediately.TIPS ON PROPER INSTALLATION1. Never install any receiver in a closed-in recess, cubbyhole, or closely fittingshelf

17、 space over, or close to, a heat duct, or in the path of heated air flow.2. Avoid conditions of high humidity such as: outdoor patio installations wheredew is a factor, near steam radiators where steam leakage is a factor, etc.3. Avoid placement where draperies may obstruct venting. The customershou

18、ld also avoid the use of decorative scarves or other coverings thatmight obstruct ventilation.4. Wall- and shelf-mounted installations using a commercial mounting kit mustfollow the factory-approved mounting instructions. A product mounted to ashelf or platform must retain its original feet (or the

19、equivalent thickness inspacers) to provide adequate air flow across the bottom. Bolts or screwsused for fasteners must not touch any parts or wiring. Perform leakage testson customized installations.5. Caution customers against mounting a product on a sloping shelf or in a tilt-ed position, unless t

20、he receiver is properly secured.6. A product on a roll-about cart should be stable in its mounting to the cart.Caution the customer on the hazards of trying to roll a cart with small cast-ers across thresholds or deep pile carpets.7. Caution customers against using extension cords. Explain that a fo

21、rest ofextensions, sprouting from a single outlet, can lead to disastrous conse-quences to home and family.A.C. Voltmeter1500 OHM10 WATTPlace this probeon each exposedmetal part.Good Earth Groundsuch as the WaterPipe, Conduit, etc.0.15uFPRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS1-4SERVIC

22、ING PRECAUTIONSCAUTION : Before servicing the VCR+DVD covered by thisservice data and its supplements and addends, read and fol-low the SAFETY PRECAUTIONS. NOTE : if unforeseen cir-cumstances create conflict between the following servicingprecautions and any of the safety precautions in this publi-c

23、ations, always follow the safety precautions.Remembers Safety First:General Servicing Precautions1. Always unplug the VCR+DVD AC power cord from the ACpower source before:(1)Removing or reinstalling any component, circuit board, module, or any other assembly.(2)Disconnection or reconnecting any inte

24、rnal electricalplug or other electrical connection.(3)Connecting a test substitute in parallel with an elec-trolytic capacitor.Caution : A wrong part substitution or incorrect polarity installation of electrolytic capacitors may resultin an explosion hazard.2. Do not spray chemicals on or near this

25、VCR+DVD or anyof its assemblies.3. Unless specified otherwise in this service data, cleanelectrical contacts by applying an appropriate contact cleaning solution to the contacts with a pipe cleaner,cotton-tipped swab, or comparable soft applicator.Unless specified otherwise in this service data, lub

26、ricationof contacts is not required.4. Do not defeat any plug/socket B+ voltage interlocks withwhitch instruments covered by this service manual mightbe equipped.5. Do not apply AC power to this VCR+DVD and/or any of itselectrical assemblies unless all solid-state device heatsinks are cerrectly inst

27、alled.6. Always connect test instrument ground lead to theappropriate ground before connection the test instrumentpositive lead. Always remove the test instrument ground lead last.Insulation Checking ProcedureDisconnect the attachment plug from the AC outlet and turnthe power on. Connect an insulati

28、on resistance meter(500V)to the blades of the attachment plug. The insulation resis-tance between each blade of the attachment plug and acces-sible conductive parts (Note 1) should be more than 1M-ohm.Note 1 : Accessible Conductive Parts including Metal pan-els, Input terminals, Earphone jacks, etc.

29、Electrostatically Sensitive (ES) DevicesSome semiconductor (solid state) devices can be damagedeasily by static electricity. Such components commonly arecalled Electrostatically Sensitive (ES) Devices. Examples oftypical ES devices are integrated circuits and some fieldeffect transistors and semicon

30、ductor 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 compo-nent or semiconductor-equipped assembly, drain off anyelectrostatic charge on your body by touching a kno

31、wnearth ground. Alternatively, obtain and wear a commer-cially 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 condu

32、ctive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.3. Use only a grouned-tip soldering iron to solder or unsolderES devices.4. Use only an anti-static solder removal device. Somesolder removal devices not classified a “anti-static” cangenerate el

33、ectrical charges sufficient to damage ES devices.5. Do not use freon-propelled chemicals. These cangenerate electrical charge sufficient to damage ESdevices.6. Do not remove a replacement ES device from its protective package until immediately before you are ready toinstall it. (Most replacement ES

34、devices are packaged withleads electrically shorted together by conductive foam,aluminum foil, or comparable conductive material).7. Immediately before removing the protective material fromthe leads of a replacement ES device, touch the protectivematerial to the chassis or circuit assembly into whic

35、h thedevice will be installed.Caution : Be sure no power is applied to the chassis orcircuit, and observe all other safety precautions.8. Minimize bodily motions when handling unpackaged replacement ES devices. (Normally harmless motion such as the brushing together of your clothes fabric or the lif

36、tingof your foot from a carpeted floor can generate static elec-tricity sufficient to damage an ES device.)1-5SPECIFICATIONS GENERALPower requirementsAC 120V , 60 HzPower consumption19W Dimensions (approx.)430 X 78.5 X 275 mm (16.9 X 3.1 X 10.8 inches) (w x h x d)Mass (approx.)8.8 lbs (4.0 kg) Opera

37、ting temperature5C to 40C (41F to 104F)Operating humidity5 % to 90 %Signal systemNTSC INPUTSANTENNA IN75 ohms (VHF/UHF/CATV)VHS VIDEO IN (LINE1, 2)1 Vp-p 75 ohms, sync negative, RCA jack x 2VHS AUDIO IN (LINE1, 2)-6.0 dBm more than 47 kohms, RCA jack (L, R) x 2 OUTPUTSVIDEO OUT1 Vp-p 75 ohms, sync n

38、egativeS-VIDEO OUT(Y) 1.0 V (p-p), 75 ohms, negative sync, Mini DIN 4-pin x 1(C) 0.286 V (p-p) 75 ohmsCOMPONENT VIDEO OUT(Y) 1.0 V (p-p), 75 ohms, negative sync, RCA jack x 1(Progressive Scan)(Pb)/(Pr) 0.7 V (p-p), 75 ohms, RCA jack x 2Audio output (digital audio)0.5 V (p-p), 75 ohms, RCA jack x 1Au

39、dio output (optical audio)5 V (p-p), 75 , Optical connector x 1Audio output (analog audio)2.0 Vrms (1 KHz, 0 dB), 330 ohms, RCA jack (L, R) x 1RF OUTChannel 3 or 4 (Switchable) VCR SpecificationsHead systemFour head helical scan azimuth systemTimer12-hour display type with AM, PMTape speed SP: 33.35

40、 mm/sec, LP: 16.67 mm/sec, SLP: 11.12 mm/secTape width12.7 mmMaximum recording timeSP: 2 HOURS (T-120), SLP: 6 HOURS (T-120)/8 HOURS (T-160)Rewind timeAbout 3 minutes (T-120)Antenna75 ohms (VHF/UHF)VHF output signalChannel 3 or 4 (Switchable)Channel coverageVHF: 2-13, UHF: 14-69, CATV: 1-125 (4A, A-

41、W, W+1 - W+84, A-5 -A-1)Frequency range20Hz to 20kHzSignal-to-noise ratioMore than 43dBDynamic rangeMore than 88 dBChannel separationMore than 60 dB DVD SpecificationsLaser systemSemiconductor laser, wavelength 650 nmFrequency responseDVD (PCM 96 kHz): 8 Hz to 44 kHz, DVD (PCM 48 kHz): 8 Hz to 22 kH

42、zCD: 8 Hz to 20 kHzSignal-to-noise ratioMore than 100dB (ANALOG OUT jacks only)Harmonic distortionLess than 0.008%Dynamic rangeMore than 95 dB (DVD/CD) Accessories:Video cable x 1, Audio cable x 1, RF 75-ohm Coaxial Cable x 1, Remote control x 1, Batteries(AAA) x 22-1SECTION 2CABINET & MAIN CHASSISC

43、ONTENTSEXPLODED VIEWS.2-21. Cabinet and Main Frame Section.2-22. Packing Accessory Section.2-32-2EXPLODED VIEWS1. Cabinet and Main Frame Section280A43A60A50260A44A26A00250300276462467467457467A46A47468468468323265467465330452452261A261A261A261A285274283284286A54321BCD2-32. Packing Accessory SectionB

44、ATTERY808BAG804PACKING, CASING803806INSTRUCTION ASSEMBLY CABLE(COAXIAL)810 CABLE ASSY RF801REMOTE CONTROLLERASSEMBLY900BOX802PACKING, CASING803811812PLUG ASSY 1WAYPLUG ASSY 2WAY3-13-1SECTION 3ELECTRICALCONTENTSOVERALL WIRING DIAGRAM.3-2VCR PARTELECTRICAL ADJUSTMENTPROCEDURES.3-3ELECTRICALTROUBLESHOO

45、TING GUIDE.3-41. POWER(SMPS) CIRCUIT .3-42. SYSTEM/KEY CIRCUIT .3-73. SERVO CIRCUIT.3-84. OSD CIRCUIT.3-105. Y/C CIRCUIT.3-116. HI-FI CIRCUIT.3-157. TUNER/IF CIRCUIT.3-18BLOCK DIAGRAMS.3-201. POWER (SMPS) BLOCK DIAGRAM.3-202. TU/IF BLOCK DIAGRAM.3-223. Y/C BLOCK DIAGRAM.3-244. NORMAL AUDIO BLOCK DIA

46、GRAM.3-265. HI-FI BLOCK DIAGRAM.3-286. SYSTEM BLOCK DIAGRAM .3-30CIRCUIT DIAGRAMS.3-321. POWER (SMPS) CIRCUIT DIAGRAM.3-322. TU/IF CIRCUIT DIAGRAM .3-343. A/V CIRCUIT DIAGRAM .3-364. HI-FI CIRCUIT DIAGRAM .3-385. JACK CIRCUIT DIAGRAM.3-406. SYSTEM CIRCUIT DIAGRAM.3-427. KEY CIRCUIT DIAGRAM.3-448. TI

47、MER CIRCUIT DIAGRAM.3-46 WAVEFORMS.3-48 CIRCUIT VOLTAGE CHART.3-50PRINTED CIRCUIT DIAGRAMS.3-521. MAIN P.C.BOARD .3-522. MAIN P.C.BOARD .3-543. POWER P.C.BOARD.3-564. POWER P.C.BOARD.3-585. POWER P.C.BOARD.3-58DVD PARTELECTRICAL TROUBLESHOOTINGGUIDE & WAVEFORMS.3-601. SYSTEM OPERATION FLOW.3-602. TE

48、ST & DEBUG FLOW.3-61DETAILS AND WAVEFORMS ONSYSTEM TEST AND DEBUGGING.3-671. SYSTEM 27MHZ CLOCK, RESET, FLASH R/W SIGNAL.3-672. SDRAM CLOCK .3-693. TRAY OPEN/CLOSE SIGNAL.3-694. SLED CONTROL RELATED SIGNAL(NO DISC CONDITION).3-715. LENS CONTROL RELATED SIGNAL(NO DISC CONDITION).3-716. LASER POWER CO

49、NTROL RELATEDSIGNAL(NO DISC CONDITION).3-727. DISC TYPE JUDGEMENT WAVEFORM .3-728. FOCUS ON WAVEFORM.3-749. SPINDLE CONTROL WAVEFORM(NO DISC CONDITION).3-7510. TRACKING CONTROL RELATEDSIGNAL(SYSTEM CHECKING) .3-7611. RF WAVEFORM.3-7712. MT1379 AUDIO OPTICAL AND COAXIAL OUTPUT (ASPDIF).3-7713. MT1379

50、 VIDEO OUTPUT WAVEFORM.3-7814. AUDIO OUTPUT FROM AUDIO DAC.3-79BLOCK DIAGRAMS.3-811. OVERALL BLOCK DIAGRAM.3-81 2. SERVO BLOCK DIAGRAM.3-82 3. MPEG & MEMORY BLOCK DIAGRAM.3-834. VIDEO & AUDIO BLOCK DIAGRAM.3-84CIRCUIT DIAGRAMS.3-851. SYSTEM CIRCUIT DIAGRAM.3-852. RF & DSP SERVO CIRCUIT DIAGRAM.3-874