LG-DP270B-dvd-sm 维修电路原理图.pdf

PORTABLE DVDSERVICE MANUALMODEL : DP270BCAUTIONBEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”IN THIS MANUAL.MODEL : DP270BSERVICE MANUALP/NO : AFN33673353 APRIL, 2007http:/Av. Sor Juana lns de la Cruz No 555Col. San LorenzoTlalnepantla, Estado de Mxico CP 54033Tel. 321 19 00 Fax. 5 657549Lada sin costo 01 800 50 481 00RadioFans.CN 收音机爱 好者资料库CONTENTSSECTION 1.SUMMARYSECTION 2.EXPLODED VIEWSSECTION 3.ELECTRICALSECTION 4.REPLACEMENT PARTS LISTRadioFans.CN 收音机爱 好者资料库1-2SECTION 1SUMMARYCONTENTSPRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS.1-3SERVICING PRECAUTIONS.1-4 GENERAL SERVICING PRECAUTIONS INSULATION CHECKING PRODEDURE ELECTROSTATICALLY SENSITIVE (ES) DEVICESSPECIFICATIONS.1-51-3PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTSIMPORTANT SAFETYNOTICEThis manual was prepared for use only by properly trained audio-video servicetechnicians.When servicing this product, under no circumstances should the original design bemodified or altered without permission from LG Corporation. All components shouldbe replaced only with types identical to those in the original circuit and their physicallocation, wiring and lead dress must conform to original layout upon completion ofrepairs.Special components are also used to prevent x-radiation, shock and fire hazard.These components are indicated by the letter “x” included in their componentdesignators and are required to maintain safe performance. No deviations areallowed without prior approval by LG Corporation.Circuit diagrams may occasionally differ from the actual circuit used. This way,implementation of the latest safety and performance improvement changes into theset is not delayed until the new service literature is printed.CAUTION: Do not attempt to modify this product in any way. Never performcustomized installations without manufacturers approval. Unauthorizedmodifications will not only void the warranty, but may lead to property damage or userinjury.Service work should be performed only after you are thoroughly familiar with thesesafety checks and servicing guidelines.GRAPHIC SYMBOLSThe exclamation point within an equilateral triangle is intended to alertthe service personnel to important safety information in the serviceliterature.The lightning flash with arrowhead symbol within an equilateraltriangle is intended to alert the service personnel to the presence ofnoninsulated “dangerous voltage” that may be of sufficient magnitudeto constitute a risk of electric shock.The pictorial representation of a fuse and its rating within an equilateraltriangle is intended to convey to the service personnel the followingfuse replacement caution notice:CAUTION : FOR CONTINUED PROTECTION AGAINST RISK OFFIRE, 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. Afterthe original service problem has been corrected, make a check of the following: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 and fromthe repair shop.2. Verify that all protective devices such as insulators, barriers, covers, shields, strainreliefs, power supply cords, and other hardware have been reinstalled per theoriginal design. Be sure that the safety purpose of the polarized line plug has notbeen defeated.3. Soldering must be inspected to discover possible cold solder joints, soldersplashes, 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 or damaged insulation (including the AC cord), and replace ifnecessary.5. No lead or component should touch a high current device or a resistor rated at 1watt or more. Lead tension around protruding metal surfaces must be avoided.6. After reassembly of the set, always perform an AC leakage test on all exposedmetallic parts of the cabinet (the channel selector knobs, antenna terminals,handle and screws) to be sure that set is safe to operate without danger ofelectrical shock. DO NOT USE ALINE ISOLATION TRANSFORMER DURINGTHIS TEST. Use an AC voltmeter having 5000 ohms per volt or more sensitivityin the following manner: Connect a 1500 ohm, 10 watt resistor, paralleled by a .15mfd 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 ACvoltage across the combination of 1500 ohm resistor and .15 mfd capacitor.Reverse the AC plug by using a non-polarized adaptor and repeat AC voltagemeasurements for each exposed metallic part. Voltage measured must notexceed 0.75 volts RMS. This corresponds to 0.5 milliamp AC. Any valueexceeding this limit constitutes a potential shock hazard and must be correctedimmediately.TIPS ON PROPER INSTALLATION1. Never install any receiver in a closed-in recess, cubbyhole, or closely fitting shelfspace 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 where dewis a factor, near steam radiators where steam leakage is a factor, etc. 3. Avoid placement where draperies may obstruct venting. The customer should alsoavoid the use of decorative scarves or other coverings that might obstructventilation.4. Wall- and shelf-mounted installations using a commercial mounting kit must followthe factory-approved mounting instructions. A product mounted to a shelf orplatform must retain its original feet (or the equivalent thickness in spacers) toprovide adequate air flow across the bottom. Bolts or screws used for fastenersmust not touch any parts or wiring. Perform leakage tests on customizedinstallations.5. Caution customers against mounting a product on a sloping shelf or in a tiltedposition, unless the receiver is properly secured.6. Aproduct 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 castersacross thresholds or deep pile carpets.7. Caution customers against using extension cords. Explain that a forest ofextensions, sprouting from a single outlet, can lead to disastrous consequences tohome and family.1-4SERVICING PRECAUTIONSCAUTION: Before servicing the PORTABLE DVD coveredby this service data and its supplements and addends, readand follow the SAFETYPRECAUTIONS. NOTE: ifunforeseen circumstances create conflict between thefollowing servicing precautions and any of the safetyprecautions in this publications, always follow the safetyprecautions.Remember Safety First :General Servicing Precautions1.Always unplug the PORTABLE DVD AC power cord fromthe AC power source before:(1) Removing or reinstalling any component, circuit board,module, or any other assembly.(2) Disconnecting or reconnecting any internal electricalplug or other electrical connection.(3) Connecting a test substitute in parallel with anelectrolytic capacitor.Caution : A wrong part substitution or incorrect polarityinstallation of electrolytic capacitors may result in anexplosion hazard.2.Do not spray chemicals on or near this PORTABLE DVDor any of its assemblies.3.Unless specified otherwise in this service data, cleanelectrical contacts by applying an appropriate contactcleaning solution to the contacts with a pipe cleaner,cotton-tipped swab, or comparable soft applicator. Unless specified otherwise in this service data, lubricationof contacts is not required.4.Do not defeat any plug/socket B+ voltage interlocks withwhich instruments covered by this service manual mightbe equipped.5.Do not apply AC power to this PORTABLE DVD and / orany of its electrical assemblies unless all solid state deviceheat sinks are correctly installed.6.Always connect the test instrument ground lead to anappropriate ground before connecting the test instrumentpositive lead. Always remove the test instrument groundlead last.Insulation Checking ProcedureDisconnect the attachment plug from the AC outlet and turnthe power on. Connect an insulation resistance meter (500V)to the blades of the attachment plug. The insulationresistance between each blade of the attachment plug andaccessible conductive parts (Note 1) should be more than1Mohm.Note 1: Accessible Conductive Parts include Metal panels,Input terminals, Earphone jacks,etc.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 semiconductor chip components.The following techniques should be used to help reduce theincidence of component damage caused by static electricity.1.Immediately before handling any semiconductorcomponent or semiconductor-equipped assembly, drain offany electrostatic charge on your body by touching a knownearth ground. Alternatively, obtain and wear acommercially available discharging wrist strap device,which should be removed for potential shock reasons priorto applying power to the unit under test.2.After removing an electrical assembly equipped with ESdevices, place the assembly on a conductive surface suchas aluminum foil, to prevent electrostatic charge buildup orexposure of the assembly.3.Use only a grounded-tip soldering iron to solder orunsolder ES devices.4.Use only an anti-static solder removal device. Some solderremoval devices not classified as “anti-static” can generateelectrical charges sufficient to damage ES devices.5.Do not use freon-propelled chemicals. These can generatean electrical charge sufficient to damage ES devices.6.Do not remove a replacement ES device from itsprotective package until immediately before you are readyto install it. (Most replacement ES devices are packagedwith leads electrically shorted together by conductivefoam, 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 which 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 unpackagedreplacement ES devices. (Normally harmless motion suchas the brushing together of your clothes fabric or the liftingof your foot from a carpeted floor can generate staticelectricity sufficient to damage an ES device.)1-5SPECIFICATIONS DVD PLAYERPower supplyDC 12V (AC adapter terminal), DC 7.4V (Battery)Power consumption12W with batteryWeight190.4g (0.56kg)(without battery pack)External dimensions(W X D X H)(191 X 74 X 39mm)Signal systemNTSLLaserSemiconductor laser, wavelength 655nm (DVD),790nm(CD)Frequency range (audio)DVD linear sound:48kHZ sampling 4HZ to 20kHZ96KHZ sampling4HZ to 44kHZSignal-to-noise ratio(audio)More than 85dBDynamic range(audio)More than 85dBHarmonic distortion(audio)0.08%Operatingconditions(audio)Temperature: 41F to 95F, Operation status: Horizontal CONNECTORSVideo input/output(VIDEO IN/OUT)2.6x7.8(10/0, 10BC +28/0.10BC) *3F L=1200MMAudio input/output 2.0Vrms (1 KHZ,0 dB), 3.5m X 1(AUDIO IN/OUT, analog audio)Earphone terminal3.5mm stereo mini jack X 1 LIQUID CRYSTAL DISPLAYPanel size7inches (16:9)Projection systemTN color transmissionDriving systemTFT active matrix SUPPLIED ACCESSORIESRC Aaudio/Video cable1AC Adapter (AD-DP40)1Power Cord1Battery Pack (DP-BT50)1Remote control1Battery for Remote control (Lithium)12-1SECTION 2EXPLODED VIEWSCONTENTSEXPLODED VIEWS.2-21. CABINET AND MAIN FRAME SECTION.2-23. PACKING ACCESSORY SECTION.2-32-2A48A40274293260286275281454455A00455A53296295298297451299284285CABLE1453262267251252253272277A51261264277A46AA45AFRONTBOARDLCDBOARDKEYBOARDMAIN BOARD283809A42A46CABLE3453266278CABLE2279EXPLODED VIEWS1. CABINET AND MAIN FRAME SECTION2-32. PACKING ACCESSORY SECTION808 BATTERY802A BOX INNER834 CABLE, CIJAR JACK806 PLUG ASSY833 ADAPTER900 REMOTE CONTROL801 OWNERS MANUAL804 PACKING SHEET803 PACKING802 BOX CARTON3-1SECTION 3ELECTRICALCONTENTSLCD PART.3-2LCD ELECTRICAL TROUBLESHOOTING GUIDE.3-3BLOCK DIAGRAM.3-5CIRCUIT DIAGRAM.3-7PRINTED CIRCUIT DIAGRAM.3-9MAIN PART.3-11MAIN ELECTRICAL TROUBLESHOOTING GUIDE.3-111. POWER (DC-DC CONVERTER) CIRCUIT.3-112. MPEG CIRCUIT .3-143. RF/SERVO CIRCUIT.3-15DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING.3-191. SYSTEM 27MHZ CLOCK, RESET & FLASH R/W SIGNAL.3-192. SDRAM CLOCK.3-193. DISC TYPE JUDGEMENT WAVEFORM.3-204. FOCUS ON WAVEFORM.3-225. SPINDLE CONTROL WAVEFORM (NO DISC CONDITION).3-226. TRACKING CONTROL RELATED SIGNAL (SYSTEM CHECKING) .3-237. MT1389 AUDIO OPTICAL AND COAXIAL OUTPUT (ASPDIF) .3-248. MT1389 VIDEO OUTPUT WAVEFORM .3-249. AUDIO OUTPUT FROM AUDIO DAC.3-25WIRING CONNECTION DIAGRAMS.3-261. WIRING CONNECTION DIAGRAM 1.3-262. WIRING CONNECTION DIAGRAM 2.3-27BLOCK DIAGRAMS.3-281. OVERALL BLOCK DIAGRAM.3-282. POWER BLOCK DIAGRAM.3-293. SERVO BLOCK DIAGRAM.3-304. SYSTEM BLOCK DIAGRAM.3-315. AV BLOCK DIAGRAM.3-32CIRCUIT DIAGRAMS.3-331. MPEG CIRCUIT DIAGRAM .3-332. MEMORY CIRCUIT DIAGRAM.3-353. OPU & MOTOR CIRCUIT DIAGRAM .3-374. AV CIRCUIT DIAGRAM.3-395. CHARGE CIRCUIT DIAGRAM.3-416. FM-TX (OPTION) CIRCUIT DIAGRAM.3-437. PANEL I/F CIRCUIT DIAGRAM .3-458. MENU KEY CIRCUIT DIAGRAM.3-479. FRONT KEY CIRCUIT DIAGRAM .3-49 CIRCUIT VOLTAGE CHART.3-51PRINTED CIRCUIT DIAGRAMS.3-551. MAIN P.C.BOARD.3-552. KEY MENU P.C.BOARD .3-593. KEY FRONT P.C.BOARD.3-593-2LCD PART1) Power measuringMeasure each power after power supply.C902(-) : -10V, C901(+) : +15V, C916(+) : +7.5V, C918(+) : +5VD, C914 : 3.3V 2) VCOM waveform adjustmentAdjust the VCOM level while changing the VR901 as below waveform by using the scope in theC921.Vcom Waveform0.17V3.72V68.22s3.89VGND3-3LCD ELECTRICAL TROUBLESHOOTING GUIDEFuse normal?Fuse ReplaceYESYESNODisplay condition?Inverter abnormalNOAppear shadow forminterference in black backgroundIC(U1) normal operateIC(U1) Check and ReplaceYESNO+5V normal?IC(U901) Check and ReplaceYESYESNO7.5V, 15V, -10V normal?D907, D901, D902NOMain B/D on locatedRGB signal output?Check and ReplaceMPEG1389. (Pin : 184, 185, 187)YESNOIC(U902) and ReplaceVCOM signal? (4.5V)NO3-4LCD ELECTRICAL TROUBLESHOOTING GUIDELCD MODE CONT signal?All “LOW” (Normal condition?MAIN B/D CheckYESNOTFT LCD pressure voltage?+15V, -14V, +5VPower source and D901, D902, U901 CheckYESNOTFT LCD normal?ReplaceYESNOColor adjusting normal?Readjust as adjustement standardYESEach connector?Replace and ReassembleYESNOReplaceENDNO3-5STVR STVL CKV UND OEV VCOMO LNR MODOEH STHL STHR CPH3 CPH2 CPH1 89P_ R 89P_ G 89P_ B SP L-SP L+ SP R-SP R+ 3.3V BAT_ OUT PWRCTL_ LCD VCOM BLOCKNJM3414A IC VOLTAGE SUPPLY SMOTHLYLCD POWER BLOCKVGH (15V) VGL (-1 0V) 7.5V 5V MP1540 IC R/G/B Circuit BLOCKROUT GOUT BOUT VCOM VGH VGL STVR STVL CKV UND OEV VCOMO LNR MODOEH STHL STHR CPH3 CPH2 CPH1 89P_ R 89P