Jvc-TUDB-1-SU-Service-Manual电路原理图.pdf

《Jvc-TUDB-1-SU-Service-Manual电路原理图.pdf》由会员分享，可在线阅读，更多相关《Jvc-TUDB-1-SU-Service-Manual电路原理图.pdf（25页珍藏版）》请在收音机爱好者资料库上搜索。

1、SERVICE MANUALCOPYRIGHT 2004 Victor Company of Japan, LimitedNo.YA2242004/11DIGITAL TERRESTRIAL SET TOP BOXYA224200411TU-DB1SUTABLE OF CONTENTS1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2、 1-32 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-43 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3、 . 1-64 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-95 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4、. . . . . . . 1-10MENUBACKPOKTV/DTV1TV324 657 980 AVTVTOP MENUSTBWIDE GUIDESUB TITLE1-2 (No.YA224)SPECIFICATIONDesign & specifications are subject to change without notice.Items ContentsDimensions ( W H D ) 28.0cm 4.0cm 18.5cmMass 1.3kgBroadcasting System DVB-T 2k & 8kRF System PALVideo System PALAu

5、dio System MPEG Layer I & II , 32kHz / 44.1kHz / 48kHz , Single / Dual channels , Stereo & joint stereoTeletext System Digital TeletextChannel Memory Number 200chChannel Coverage 47.0MHz to 858MHzPower Requirements DC6V, AC adaptor : AC100V to AC240V, 50Hz / 60HzAntenna Input 75 unbalanced, PAL type

6、 1 (5V DC active antenna supply)TV Output 75 unbalanced, PAL type 1 (Loop through)TV(SCART-1)Terminal(Input/Output)Video 1V (p-p) , 75Audio 500mV (rms) (-4dBs), 10k minRGB / Video 1V (p-p) , 75S-VideoY : 1V (p-p) positive, 75C : 0.286V (p-p) (burst signal), 75VCR(SCART-2)Terminal(Input/Output)Video

7、1V (p-p) , 75Audio 500mV (rms) (-4dBs), 10k minRGB / Video 1V (p-p) , 75S-VideoY : 1V (p-p) positive, 75C : 0.286V (p-p) (burst signal), 75Digital Audio Output SPDIF coaxial 1Remote Control Unit VE-30031949 (RM-C1890S), (AA/R06 dry battery 2)(No.YA224)1-3SECTION 1PRECAUTION1.1 SAFETY PRECAUTIONS(1)

8、The design of this product contains special hardware,many circuits and components specially for safetypurposes. For continued protection, no changes should bemade to the original design unless authorized in writing bythe manufacturer. Replacement parts must be identical tothose used in the original

9、circuits. Service should beperformed by qualified personnel only.(2) Alterations of the design or circuitry of the products shouldnot be made. Any design alterations or additions will voidthe manufacturers warranty and will further relieve themanufacturer of responsibility for personal injury orprop

10、erty damage resulting therefrom.(3) Many electrical and mechanical parts in the products havespecial safety-related characteristics. Thesecharacteristics are often not evident from visual inspectionnor can the protection afforded by them necessarily beobtained by using replacement components rated f

11、orhigher voltage, wattage, etc. Replacement parts whichhave these special safety characteristics are identified inthe parts list of Service manual. Electrical componentshaving such features are identified by shading on theschematics and by ( ) on the parts list in Servicemanual. The use of a substit

12、ute replacement which doesnot have the same safety characteristics as therecommended replacement part shown in the parts list ofService manual may cause shock, fire, or other hazards.(4) Dont short between the LIVE side ground andISOLATED (NEUTRAL) side ground or EARTH sideground when repairing. Som

13、e models power circuit is partly different in the GND.The difference of the GND is shown by the LIVE : ( ) sideGND, the ISOLATED (NEUTRAL) : ( ) side GND andEARTH : ( ) side GND. Dont short between the LIVE side GND and ISOLATED(NEUTRAL) side GND or EARTH side GND and nevermeasure the LIVE side GND

14、and ISOLATED (NEUTRAL)side GND or EARTH side GND at the same time with ameasuring apparatus (oscilloscope etc.). If above note willnot be kept, a fuse or any parts will be broken.(5) If any repair has been made to the chassis, it isrecommended that the B1 setting should be checked oradjusted (See AD

15、JUSTMENT OF B1 POWER SUPPLY).(6) The high voltage applied to the picture tube must conformwith that specified in Service manual. Excessive highvoltage can cause an increase in X-Ray emission, arcingand possible component damage, therefore operationunder excessive high voltage conditions should be ke

16、pt toa minimum, or should be prevented. If severe arcingoccurs, remove the AC power immediately and determinethe cause by visual inspection (incorrect installation,cracked or melted high voltage harness, poor soldering,etc.). To maintain the proper minimum level of soft X-Rayemission, components in

17、the high voltage circuitryincluding the picture tube must be the exact replacementsor alternatives approved by the manufacturer of thecomplete product.(7) Do not check high voltage by drawing an arc. Use a highvoltage meter or a high voltage probe with a VTVM.Discharge the picture tube before attemp

18、ting meterconnection, by connecting a clip lead to the ground frameand connecting the other end of the lead through a 10k2W resistor to the anode button. (8) When service is required, observe the original lead dress.Extra precaution should be given to assure correct leaddress in the high voltage cir

19、cuit area. Where a short circuithas occurred, those components that indicate evidence ofoverheating should be replaced. Always use themanufacturers replacement components.(9) Isolation Check (Safety for Electrical Shock Hazard) After re-assembling the product, always perform anisolation check on the

20、 exposed metal parts of the cabinet(antenna terminals, video/audio input and output terminals,Control knobs, metal cabinet, screw heads, earphone jack,control shafts, etc.) to be sure the product is safe to operatewithout danger of electrical shock.a) Dielectric Strength Test The isolation between t

21、he AC primary circuit and all metalparts exposed to the user, particularly any exposed metalpart having a return path to the chassis should withstand avoltage of 3000V AC (r.m.s.) for a period of one second. (. . . Withstand a voltage of 1100V AC (r.m.s.) to anappliance rated up to 120V, and 3000V A

22、C (r.m.s.) to anappliance rated 200V or more, for a period of one second.) This method of test requires a test equipment not generallyfound in the service trade.b) Leakage Current Check Plug the AC line cord directly into the AC outlet (do not usea line isolation transformer during this check.). Usi

23、ng a“Leakage Current Tester“, measure the leakage currentfrom each exposed metal part of the cabinet, particularlyany exposed metal part having a return path to the chassis,to a known good earth ground (water pipe, etc.). Anyleakage current must not exceed 0.5mA AC (r.m.s.). However, in tropical are

24、a, this must not exceed 0.2mA AC(r.m.s.). Alternate Check MethodPlug the AC line cord directly into the AC outlet (do notuse a line isolation transformer during this check.). Usean AC voltmeter having 1000 ohms per volt or moresensitivity in the following manner. Connect a 150010W resistor parallele

25、d by a 0.15F AC-type capacitorbetween an exposed metal part and a known good earthground (water pipe, etc.). Measure the AC voltageacross the resistor with the AC voltmeter. Move theresistor connection to each exposed metal part,particularly any exposed metal part having a return pathto the chassis,

26、 and measure the AC voltage across theresistor. Now, reverse the plug in the AC outlet andrepeat each measurement. Any voltage measured mustnot exceed 0.75V AC (r.m.s.). This corresponds to0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.3V AC(r.m.s.). This corresponds to 0.2mA A

27、C (r.m.s.).AC VOLTMETER(HAVING 1000 /V,OR MORE SENSITIVITY)PLACE THIS PROBEON EACH EXPOSEDMETAL PART1500 10W0.15 F AC-TYPEGOOD EARTH GROUND1-4 (No.YA224)SECTION 2SPECIFIC SERVICE INSTRUCTIONS2.1 INTRODUCTION TU-DB1SU is a DVB-T set-top box capable of decoding MPEG coded source. It outputs CVBS, RGB

28、and Y/C analog video and left-right analog audio. TU-DB1SU also has digital audio output. The tuner is capable of getting both digital broadcasts. The tuner is capable of receiving both VHF and UHF horizontal bands.The tuning is available through the digitally controlled I2C bus (PLL).2.2 FUNCTIONS1

29、 2 3 4 5FRONTREAR1 2 345 6 71 Standby button(Power)2 Power Indicator3 Program up button4 Program down button5 REMOTE CONTROL UNIT Sensor1 RS 232 Terminal2 TV Output3 Antenna Terminal4 TV (Scart-1) Terminal (21-pin Euro connector)5 VCR (Scart-2) Terminal (21-pin Euro conector)6 SPDIF Terminal7 DC 6V

30、Input TerminalRS 232 TV OUT ANTENNA TV VCR SPDIF 6V DC(No.YA224)1-52.3 21-PIN EURO CONNECTOR (SCART SOCKET) : PL201 / PL60120 18 16 14 12 10 8 6 4 221 19 17 15 13 11 9 7 5 3 1Pin assignmentPinPL201 : TV SCART SOCKET PL601 : VCR SCART SOCKETDescription Description1 Audio Right Output Audio Right Outp

31、ut2 Audio Right Input Audio Right Input3 Audio Left Output Audio Left Output4GND GND5GND GND6 Audio Left Input Audio Left Input7 BLUE Output BLUE Output8 Function Switching Output Function Switching Input9GND GND10 Not connected No Connection11 GREEN Output GREEN Output12 Not connected No Connection

32、13 GND GND14 GND GND15 RED Output / C Output RED Output / C Output16 Fast Blanking Output No Connection17 GND GND18 GND GND19 CVBS Output / Y Output CVBS Output / Y Output20 CVBS Input CVBS Input21 GND GND1-6 (No.YA224)SECTION 3DISASSEMBLY3.1 DISASSEMBLY PROCEDULE3.1.1 TOP COVER(1) Unplug the connec

33、ting the AC adaptor.(2) Remove the 4 the Rubber Foot .(3) Remove the 5 screws A .(4) Withdraw the TOP COVER.3.1.2 MAIN PWB Take out the TOP COVER.(1) Remove the 1 screw B .(2) Slightly raise the both sides of the MAIN PWB by hand andwithdraw the MAIN PWB backward.CAUTIONIf necessary, take off the wi

34、re clamp, connectors etc.Be careful enough when developing a MAIN PWB.3.1.3 FRONT CONTROL PWB Take out the TOP COVER.(1) Remove the 2 screws C.(2) Remove the FRONT CONTROL PWB.3.1.4 DAUGHTER PWB Take out the TOP COVER.(1) Remove the 2 screws D.(2) Remove the DAUGHTER PWB.3.1.5 BACK COVER Take out th

35、e TOP COVER.(1) Raise up the both sides and withdraw the BACK COVER.3.1.6 CHECKING THE PW BOARD To check the back side of the PW Board.(1) Pull out the PW Board. (Refer to REMOVING THE MAINPWB).(2) Erect the PW Board vertically so that you can easily checkthe back side of the PW Board.CAUTION When e

36、recting the PW Board, be careful so that there will beno contacting with other PW Board. Before turning on power, make sure that the wire connectoris properly connected.3.1.7 WIRE CLAMPING AND CABLE TYING(1) Be sure to clamp the wire.(2) Never remove the cable tie used for tying the wirestogether.Sh

37、ould it be inadvertently removed, be sure to tie the wireswith a new cable tie.(No.YA224)1-7MAIN PWBDAUGHTER PWBTOP COVERBOTTOM COVERFRAME RFRAME LBACK COVERAC ADAPTORRUBBER FOOTRUBBER FOOTFRONT CONTROLPWBPROGRAM DOWN/UP BUTTONSSENSOR LENSSTANDBYBUTTONSENSOR LENSHOLDER LED FRAMELED LENSACBD(x2)(x2)A

38、(x2)(x2)(x2)(x1)(x2)A(x1)1-8 (No.YA224)3.2 REPLACEMENT OF CHIP COMPONENT3.2.1 CAUTIONS(1) Avoid heating for more than 3 seconds. (2) Do not rub the electrodes and the resist parts of the pattern.(3) When removing a chip part, melt the solder adequately. (4) Do not reuse a chip part after removing it

39、. 3.2.2 SOLDERING IRON(1) Use a high insulation soldering iron with a thin pointed end of it. (2) A 30w soldering iron is recommended for easily removing parts. 3.2.3 REPLACEMENT STEPS 1. How to remove Chip parts Resistors, capacitors, etc.(1) As shown in the figure, push the part with tweezers anda

40、lternately melt the solder at each end. (2) Shift with the tweezers and remove the chip part.Transistors, diodes, variable resistors, etc. (1) Apply extra solder to each lead. (2) As shown in the figure, push the part with tweezers andalternately melt the solder at each lead. Shift and removethe chi

41、p part. NOTE :After removing the part, remove remaining solder from thepattern. 2. How to install Chip parts Resistors, capacitors, etc.(1) Apply solder to the pattern as indicated in the figure. (2) Grasp the chip part with tweezers and place it on thesolder. Then heat and melt the solder at both e

42、nds of thechip part. Transistors, diodes, variable resistors, etc.(1) Apply solder to the pattern as indicated in the figure. (2) Grasp the chip part with tweezers and place it on thesolder. (3) First solder lead A as indicated in the figure. (4) Then solder leads B and C. SOLDER SOLDERABCABC(No.YA224)1-9SECTION 4ADJUSTMENTThis service manual does not describe ADJUSTMENT.1-10 (No.YA224)SECTION 5TROUBLESHOOTINGThis service manual does not describe TROUBLESHOOTING.