Teac-CT-M6845-Service-Manual(1) 电路图 维修手册.pdf

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1、 SERVICE MANUAL CTM6845 68CM CTV * 2 types of chassis please check serial number of unit to determine which CCT to use. SECTION 1 HAIER CHASSIS SECTION 2 SYBER CHASSIS Brand Factory Model Serial no. from To TEAC Syber CT-M6845 3600001-49 3603120-49 TEAC Syber CT-M6845 3603121-49 3606084-49 TEAC Sybe

2、r CT-M6845 3606085-49 3610062-49 TEAC Syber CT-M6845 3800001-49 3802964-49 TEAC Syber CT-M6845 3Y00001-49 3Y02340-49 TEAC Haier CT-M6845 3Z00001-49 3Z02592-49 TEAC Haier CT-M6845 4200001-49 4202340-49 JUN03 SERVCTM6845 RadioFans.CN 收音机爱 好者资料库 UOC TDA9373 SERIES CT-M6845 S S SE E ER R RV V VI I IC C

3、CE E E MMMA A AN N NU U UA A AL L L COLOUR TELEVISION PUSH PUSH RadioFans.CN 收音机爱 好者资料库 SECTION 1: RadioFans.CN 收音机爱 好者资料库 . 2 CONTENTS 1. safety precautions.3 2. TV block diagram and PHILIPS UOC functional difference between the various IC versions .4 3 Replacement of memory IC 7 4 Service adjustme

4、nt .7 5 ICs functional description9 6 Test point waveform.12 7 All ICs/transistors voltages.13 8 Purity / convergence adjustment.14 9 List of Parts .16 . 3 1.SAFETY PRECAUTIONS 1. The design of this product contains special hardware, many circuits and components specially for safety purposes. For co

5、ntinued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Service should be performed by qualified personnel only. 2. Alterations of the design or circuitry of the

6、 products should not be made. Any design alterations or additions will void the manufacturers warranty and will further relieve the manufacturer of responsibility for personal injury or property damage resulting therefrom. 3. Many electrical and mechanical parts in the products have special safety-r

7、elated characteristics. These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are ide

8、ntified in the parts list of Service manual. Electrical components having such features are identified by shading on the schematics and by ( ！ ) on the parts list in Service manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement

9、 part shown in the parts list of Service manual may cause shock, fire, or other hazards 4. Dont short between the LIVE side ground and ISOLATED (NEUTRAL) side ground or EARTH side ground when repairing. Some models power circuit is partly different in the GND. The difference of the GND is shown by t

10、he LIVE: ( ) side GND, ISOLATED (NEUTRAL) : ( ) side GND and EARTH : ( ) side GND. Dont short between the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side GND and never measure with a measuring apparatus (oscilloscope etc.) the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side G

11、ND at the same time. If above note will not be kept, a fuse or any parts will be broken. 5. If any repair has been made to the chassis, it is recommended that the B1 setting should be checked or adjusted (See ADJUSTMENT OF B1 POWER SUPPLY). 6. The high voltage applied to the picture tube must confor

12、m with that specified in Service manual. Excessive high voltage can cause an increase in X-Ray emission, arcing and possible component damage, therefore operation under excessive high voltage conditions should be kept to a minimum, or should be prevented. If severe arcing occurs, remove the AC power

13、 immediately and determine the cause by visual inspection (incorrect installation, cracked or melted high voltage harness, poor soldering, etc.). To maintain the proper minimum level of soft X-Ray emission, components in the high voltage circuitry including the picture tube must be the exact replace

14、ments or alternatives approved by the manufacturer of the complete product. 7. Do not check high voltage by drawing an arc. Use a high voltage meter or a high voltage probe with a VTVM. Discharge the picture tube before attempting meter connection, by connecting a clip lead to the ground frame and c

15、onnecting the other end of the lead through a 10k 2W resitor to the anode button. 8. When service is required, observe the original lead dress. Extra precaution should be given to assure correct lead dress in the high voltage circuit area. Where a short circuit has occurred, those components that in

16、dicate evidence of overheating should be replaced. Always use the 9. manufacturers replacement components. 10. Isolation Check (Safety for Electrical Shock Hazard) After re-assembling the product, always perform an isolation check on the exposed metal parts of the cabinet (antenna terminals, video/a

17、udio input and output terminals, Control knobs, metal cabinet, screwheads, earphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock. 11. The surface of the TV screen is coated with a thin film which can easily be damaged. Be very careful with

18、it when handle the TV. Should the TV screen become soiled, wipe it with a soft dry cloth. Never rub it forcefully. Never use any cleaner or detergent on it. (1) Dielectric Strength Test The isolation between the AC primary circuit and all metal parts exposed to the user, particularly any exposed met

19、al part having a return path to the chassis should withstand a voltage of 3000V AC (r.m.s.) for a period of one second. (Withstand a voltage of 1100V AC (r.m.s.) to an appliance rated up to 120V, and 3000V AC (r.m.s.) to an appliance rated 200V or more, for a periode of one second.) This method of t

20、est requires a test equipment not generally found in the service trade. (2) Leakage Current Check Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Using a “Leakage Current Tester”, measure the leakage current from each exposed metal part

21、 of the cabinet, particularly any exposed metal part having a return path to the chassis, to a known good earth ground (water pipe, etc.). Any leakage current must not exceed 0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.2mA AC (r.m.s.). Alternate Check Method Plug the AC line

22、 cord directly into the AC outlet ( do not use a line isolation transformer during this check.). Use an AC voltmeter having 1000 ohms per volt or more sensitivity in the following manner. Connect a 1500 10W resistor paralleled by a 0.15F AC-type capacitor between an exposed metal part and a known go

23、od earth ground (water pipe, etc.). Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to each exposed metal part, particularly any exposed metal part having a return path to the chassis, and measure the AC voltage across the resistor. Now, reverse the plu

24、g in the AC outlet and repeat each measurement. Any voltage measured must not exceed 0.75V AC (r.m.s.). This corresponds to 0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.3V AC (r.m.s.). This corresponds to 0.2mA AC (r.m.s.) . 4 2. TV Block diagram PHILIPS UOC FUNCTIONAL DIFFER

25、ENCE BETWEEN THE VARIOUS IC VERSIONS IC VERSION 9350 9351 9352 9353936093619362936393649365936693679380 9381 93829383938493859386938793889389937093739375 9377 9378 TV rang 90 90 90 11090 90 11011011011090 90 90 90 90 11011011011090 11011090 110110 90 110 Mono inter-carrier multi-standard Sound demod

26、ulator (4.5-6.5MHz) With switch able centre frequency Audio switch TUNER SAW IF IN Y IN RF AGC V IN U IN CVBSINT CHROMA IFVO OUT CVBS/Y IN SDA SCL AUDIO OUT IK RGB OUT V OUT H OUT S TRAP Vo V2i V1i Y Cr Cb ARi2 ARi1 ALi2 ALi1 S-VHS 24C04 POWER UNIT 130V 24V 16V 8V 5V 3.3V CRT PCB V IN TDA8351 V OUT

27、H IN H OUT H OUT DY 200V +15V -15VSCREEN FOCUS TDA93XX Vi1 OUT1- OUT1+ Vi2 OUT2- OUT2+ AN7522 CRT ALo ARo C Y 4052 TDA9859 A OUTR A OUTL MAIN L MAIN R SDA/SCL AV2 R AV2 R M OUTR M OUTL AV1 L AV2 L 7 4 5 1 2 6 7 8 XS303 5V TDA9874 audio audio audio audio video video bus bus video video video . 5 Auto

28、matic volume leveling Automatic volume leveling or Subcarrier output (for comb filter applications) QSS sound IF amplifier with Separate input and AGC circuit AM sound demodulator without Extra reference circuit PAL decoder SECAM decoder NTSC decoder Horizontal geometry(E-W) Horizontal and vertical

29、zoom ROM size 32- 64k 32- 64k 32- 64k 32- 64k 64- 128 64- 128 64- 128 64- 128 64- 128 64- 128 64- 128 64- 128 16- 64k 16- 64k 16- 64k 16- 64k 16- 64k 16- 64k 16- 64k 16- 64k 16- 64k 16- 64k 32- 55k 32- 55k 32- 55k 32- 55k 32- 55k User RAM size 1k 1k 1k 1k 2k 2k 2k 2k 2k 2k 2k 2k 1k 1k 1k 1k 1k 1k 1k

30、 1k 1k 1k 2.252.252.25 2.25 2.25 Teletext 1 p 1p 1p 1p 10p10p10p10p10p10p10p10p Closed captioning Block diagram TDA93xX PS/N2 series with mono intercarrier sound demodulator . 6 7 3.REPLACEMENT OF MEMORY IC 1. MEMORY IC. This TV uses memory IC. In the memory IC are memorized data for correctly opera

31、ting the video and deflection circuits. When replacing memory IC, be sure to use IC written with the initial value of data. 2. PROCEDURE FOR REPLACING MEMORY IC (1) Power off Switch the power off and unplug the power cord from AC outlet. (2) Replace IC Be sure to use memory IC written with the initi

32、al data values. (3) Power On Plug the power cord into the AC outlet and switch the power On. (4) Check and set SYSTEM default value: 1) Press “QV” key holding about 4 second and then press “MENU1” key on the Remote control unit. Or Press “TEST” key on the Remote control unit for factory used. 2) The

33、 “TEST” will be displayed on the screen. 3) Press digital key, (Mkey) and corresponding on-screen display will be appeared. Some time “PASSWORD” on-screen display will be appeared, you need to input 828. 4) Check the setting value of the SYSTEM default value of Table below. If the value is different

34、, select items by CH+/CH- keys and set value by VOL+/VOL- keys. 5) Press “STANDBY” key again and return to the normal screen. 4.SERVICE ADJUSTMENT B1 POWER SUPPLY 1. Receive normal colour bar signal. 2. Connect DC voltmeter to VD541- and isolated ground. 3. Adjust potentiometer in power unit to get

35、the voltage as 110V 1.0V for 21 inch hereinafter, 130 1.0V for 25 inch upwards. FOCUS ADJUSTMENT 1. Receive a crosshatch signal. 2. While watching the screen, adjust the FOCUS VR to make the vertical and horizontal lines as fine and sharp as possible. BUS CONTROL ADJUSTMENT To enter BUS control mode

36、, Press “TEST” key on the Remote control unit of factory. Press “0” to “9“ key, (Mkey) and corresponding on-screen display will be appeared. On TV screen “TEST” will be indicated, this means entered bus control mode. And press following key, each function will be available. Remote Hand Unit keys M1

37、M2 M3 M0 M8 menu MENU8 V SLOPE 31 V SHIFT 31 V AMP 31 V SCOR 31 ? ? ? ? ? ? ? ? ? ? 8 MENU0 Geometrical adjustment Receive PAL standard Complete pattern signal. Adjustment steps： a) Adjust V. SLOPE, to the center horizontal line just appeare from half bottom shadow. b) Adjust V. SIZE, to get 90% of

38、vertical picture contents would be displayed on CRT. c) Adjust V. SHIFT, the center horizontal line correspond to CRT vertical center. d) Adjust H.SHIFT, to get the picture horizontal center correspond to CRT horizontal center. Receive NTSC signal and repeat above M0 and M1 adjustment. M7 Menu AGC A

39、djustment. Receive 60dB(1mV)VH colour bar pattern signal，adjust AGC value（voltage from high to low） ，） ，to noise reduce gradually and just disappeared point. M9 Menu CRTcut off and white balance adjustment. Receive white signal. a) CRT cut off adjustment. 1. Select “SC”, then automatically vertical

40、scan will be stopped. 2. Adjust SCREEN control on Flyback transformer to get the darkest single horizontal line (red, green, or blue, sometimes shows more yellow, more purple or more white). b) White balance adjustment. 1. Select RD/BD menu. 2. Adjust RD/BD to get colour temperature as x=281, y=311

41、c) Sub-Brightness adjustment. (Use stair case signal) 1. Select SB menu. 2. Adjust SB to get the darkest step being cutoff. ICs Default Settings 1 TDA9381(1.0) EK cord=NTDA9381-NG MI Items Variable Preset MIItems Variable Preset M0 AVL ON/OFF ON M4SUBCON 063 63 FSL ON/OFF ON SUBCOL 063 63 FMWS ON/OF

42、F OFF SUBSHP 063 63 FFI ON/OFF OFF SUBTINT 015 15 OSO ON/OFF ON YDLY PAL 015 12 FCO ON/OFF OFF YDLY NTSC 015 12 WOOFER ON/OFF OFF YDLY SEC 015 12 DUAL OUT 01 0 YDLY AV 015 12 Volume mode 01 1 UOC VOL ON/OFF Off CATHODE 015 15 M1 BAND 02 2 SC BRI 063 10 AV CFG* 08 3 NTSC MX USA M5OSD VPOS 063 53 VIDE

43、O OUT CVBS OSD HPOS 059 15 PIN5 NTSC WIDE 063 15 PRO 03 0 ZOOM 063 59 NENU TITLE 06 3 M2 VISION IF 38.9M E2PROM ADRESS 033 DK ON/OFF OFF E2PROM VALUE 095 BG ON/OFF ON E2PROM WRITE I ON/OFF OFF M ON/OFF OFF M8FREQUENCY 50HZ 60HZ SIF PREFER BG VSLOPE 063 31 31 AUTO SOUND ON/OFF ON VSHIFT 063 31 31 VAM

44、P 063 31 31 M3 START ON 02 0 VSCOR 063 31 31 ENGLISH ON/OFF ON HSHIFT 063 31 31 9 ARABIC ON/OFF OFF PERSIAN ON/OFF OFF M9BT 063 48 TURKISH ON/OFF OFF CT 063 48 FRANCE ON/OFF OFF SC OFF RUSSIA ON/OFF OFF RB 063 32 GB 063 32 M6 SHIPMODE RD 063 32 SEARCH SPEED 03 0 GD 063 32 M7 AGC-TOP 063 25 BD 063 32

45、 AGC-SPEED 03 2 SB 063 40 2. TDA9361(1.1) EK cord=NTDA9361-NF MI Items Variable Preset MIItems Variable Preset M0 AVL ON/OFF ON M4SUBCON 063 63 FSL ON/OFF ON SUBCOL 063 63 FMWS ON/OFF OFF SUBSHP 063 63 FFI ON/OFF OFF SUBTINT 015 15 OSO ON/OFF ON YDLY PAL 015 12 FCO ON/OFF OFF YDLY NTSC 015 12 WOOFER

46、 ON/OFF OFF YDLY SEC 015 12 DUAL OUT 01 0 YDLY AV 015 12 Volume mode 01 1 UOC VOL ON/OFF Off CATHODE 015 15 M1 BAND 02 2 SC BRI 063 10 AV CFG* 08 3 NTSC MX USA M6LOGO ON/OFF ON VIDEO OUT CVBS LOGO COLUR 07 0 PIN5 NTSC LOGO POSITION 011 0 PRO 03 0 LOGO CHAR SHIPMODE M2 VISION IF 38.9M SEARCH SPEED 03 0 DK ON/OFF OFF BG ON/OFF ON M7AGC-TOP 063 25 I ON/OFF OFF AGC-SPEED 03 2 M ON/OFF OFF SIF PREFER BG M8FREQUENCY 50HZ 60HZ AUTO SOUND ON/OFF ON VSLOPE 063 31 31 VSHIFT 063 31 31 M3 START ON 02 0 VAMP 063 31 31 ENGLISH ON/OFF ON VSCOR 063 31 31 ARABIC ON/OFF OFF HSHIFT 063 31 31 PE