Teac-EU-80-ST-Service-Manual 电路图 维修手册.pdf

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1、 SERVICE MANUAL EU-80ST 80cm CTV Effective: JANUARY,2000 EU80SERV RadioFans.CN 收音机爱 好者资料库 TECHNICAL BULLETIN 1-March-2000 Page 1 of 1 MODEL: EU-80ST PROBLEM: Color purity problem File: EU80 deg cap.doc A missing capacitor in the degaussing circuit of some units can be the cause of poor color purity.

2、 The problem is visible when displaying a red or a white test pattern field. Instructions 1. Check if a 100nF 275 V AC capacitor is connected in parallel with the degaussing coil. This component should be located on the solder side of the auxiliary PCB where the degaussing thermistor is mounted. 2.

3、If the capacitor mentioned in step 1 is missing, connect a 100nF 275 V AC capacitor to the terminals of the degaussing coil connector PL201 Regards, Alcides Berta TEAC Australia Pty Ltd. RadioFans.CN 收音机爱 好者资料库 TECHNICAL BULLETIN 1-March-2000 Page 1 of 1 MODEL: EU-80ST PROBLEM: Color purity problem

4、File: EU80 deg cap.doc A missing capacitor in the degaussing circuit of some units can be the cause of poor color purity. The problem is visible when displaying a red or a white test pattern field. Instructions 1. Check if a 100nF 275 V AC capacitor is connected in parallel with the degaussing coil.

5、 This component should be located on the solder side of the auxiliary PCB where the degaussing thermistor is mounted. 2. If the capacitor mentioned in step 1 is missing, connect a 100nF 275 V AC capacitor to the terminals of the degaussing coil connector PL201 Regards, Alcides Berta TEAC Australia P

6、ty Ltd. RadioFans.CN 收音机爱 好者资料库 TECHNICAL BULLETIN 02-Jun-00 Page 1 of 1 MODEL: EU-51/80 ST PROBLEM: Power supply problem File: EU51-80 chopper tb.doc The chopper transistor Q802 is damaged as a consequence of a fault in D816. This problem normally occurs when a diode type UF5407 is used in the posi

7、tion D816. Instructions Replace damaged components. Use only a diode type BMY36D for the position D816. Regards, Alcides Berta TEAC Australia Pty Ltd. TECHNICAL BULLETIN 26-Jun-00 Page 1 of 1 MODEL: EU 51 / 66 / 68 / 80 ST PROBLEM: CRT output IC protection File: EU51-80 spgap tb.doc This is a tentat

8、ive solution to avoid damages to the output video amplifier IC901 (TDA6107) caused by electric discharges between electrodes of the CRT. The modification should be applied to units found with damaged video amplifier IC. Instructions Add the following components to the CRT board. Refer to the figure

9、and table below for parts location and specifications. Components information Item Part Number Description From To Comments 1 EUSPARK 300V Spark gap Point G Aqua 2 EUSPARK 300V Spark gap Ground Aqua Spark gap devices have no polarity 3 QDTBOUZ6R2BS Zenner diode 6V2 400 mW 1-PL901 (Cathode) Ground (A

10、node) Regards, Alcides Berta TEAC Australia Pty Ltd. 1 2 DO NOT CHANGE ANY MODULE UNLESS THE SET IS SWITCH OFF The mains supply side of the switch mode power supply transformer is live. Use an isolating transformer. The receivers fulfill completely the safety requirements. Safety precautions: Servic

11、ing of this TV should only be carried out by a qualified person. - Components marked with the warning symbol on the circuit diagram are critical for safety and must only be replaced with an identical component. - Power resistor and fusable resistors must be mounted in an identical manner to the orig

12、inal component. - When servicing this TV, check that the EHT does not exceed 26kV. TV Set switched off: Make short-circuit between HV-CRT clip and CRT ground layer. Short C804 (150mF) before changing IC802 or other components in primary side of SMPS. Measurements: Voltage readings and oscilloscope t

13、races are measured under following conditions. Antenna signal 60dB from colourbar generator. (100% white, 75% colour saturation) Brightness, contrast, colour set for a normal picture. Mains supply, 220VAC, 50Hz. PERI-TV SOCKET SCART 1 (SC050)SCART 2 (SC051) 1Audio right output0.5Vrms / 1K1Audio righ

14、t output0.5Vrms / 1K 2Audio right input0.5Vrms / 10K2Audio right input0.5Vrms / 10K 3Audio left output0.5Vrms / 1K3Audio left output0.5Vrms / 1K 4Ground AF4Ground AF 5Ground Blue5Ground Blue 6Audio left input0.5Vrms / 10K6Audio left input0.5Vrms / 10K 7Blue input0.7Vpp / 75ohm7Blue input0.7Vpp / 75o

15、hm 8AV switching input0-12VDC /10K8AV switching input0-12VDC /10K 9Ground Green9Ground Green 10-10 - 11Green input0.7Vpp / 75ohm11 - 12-12 - 13Ground Red13 Ground Red 14Ground Blanking14 Ground Blanking 15Red input0.7Vpp / 75ohm15 - 16Blanking input0-0.4VDC, 1-3VDC / 75ohm16 - 17Ground CVS output17

16、Ground CVS output 18Ground CVS input18 Ground CVS input 19CVS output1Vpp / 75ohm19 CVS output1Vpp / 75ohm 20CVS input1Vpp / 75ohm20 CVS input1Vpp / 75ohm 21Ground21 Ground * * ALL WIRES TO FRONT PANEL the device will then synchronise to the periodic frame flag bit C0. The status of the NICAM decoder

17、 can be read out from the NICAM status register by the user. The OSB bit indicates that the decoder has locked to the NICAM data. The VDSP bit indicates that the decoder has locked to the NICAM data and that the data is valid sound data. 7. SOUND OUTPUT STAGE TDA2614/TDA2615/TDA2616Q TDA2614 is used

18、 as the AF output amplifier for mono applications. It is supplied by 12VDC coming from a separate winding in the SMPS transformer. An output power of 2*6W (THD=0.5%) can be delivered into an 8ohm load. TDA2615 is used as the AF output amplifier for stereo applications. It is supplied by 12VDC coming

19、 from a separate winding in the SMPS transformer. An output power of 2*6W (THD=0.5%) can be delivered into an 8ohm load. TDA2616Q is used as the AF output amplifier for stereo and dolby prologic applications. It is supplied by 16VDC coming from a separate winding in the SMPS transformer. An output p

20、ower of 2*12W (THD=0.5%) can be delivered into an 8ohm load. 6 8. VERTICAL OUTPUT STAGE WITH TDA8351/8356 The TDA8351/8356 vertical deflection circuit can be used in 90? and 110? deflection systems with field frequencies from 50 up to 120Hz. With its bridge configuration the deflection output can be

21、 DC coupled with few external components. Only a single supply voltage for the scan and a second supply for the flyback are needed. The TDA8356 is intended for 90? systems and the TDA8351 is intended for 110? systems. The drive voltage is amplified by an amplifier and fed to two amplifiers, one is i

22、nverting and the other is a non inverting amplifier. The outputs (pins 7 and 4) are connected to the series connection of the vertical deflection coil and feedback resistor Rsense (R702/R703). The voltage across Rsense is fed via pin 9 to correction amplifier, to obtain a deflection current which is

23、 proportional to the drive voltage. The supply voltage for the TDA8351/8356 is 15VDC at pin 3. The supply voltage generator has a separate supply voltage of 45VDC at pin 6. 9. VIDEO OUTPUT AMPLIFIER TDA6107Q The TDA6107Q consists of three monolithic video output amplifiers. The amplifier can be seen

24、 as an operational amplifier with negative feedback. The advantage of negative feedback is that the amplifier characteristics do not play an important role up to certain frequencies. The internal flash diodes protect the amplifiers against flash over in the picture tube. The only protections require

25、d at the cathode outputs are a flash resistor and a sparkgap. The TDA6107Q has an internal thermal protection circuit which gives a decrease of the slew rate at high temperatures. Furthermore, the device needs only one power supply voltage (Vdd). In contrast to previous types of DMOS video amplifier

26、s, all the external resistors (Rf, Ri and Ra) are integrated, so the gain is fixed and saves 9 resistors. Furthermore, the reference voltage is integrated, it saves a resistor divider and a decoupling capacitor. So, the replacement value of the TDA6107Q is very high. The TDA6107Q is provided with a

27、black current data pin. Since TDA884X is used as drive device, no adjustments are required for gain and black setting, as the TDA884X has IC white point adjustment and black current set-up. 10.SINGLE/MULTISTANDARD VIF/SIF-PLL and FM-PLL/AM DEMODULATOR TDA9818 The TDA9818is an IC for multistandard vi

28、sion IF signal processing, sound AM and FM demodulation. It is a gain controlled wide band VIF-amplifier (AC-coupled). It is applicable for IF frequencies of 38.9 MHz, 45.75 MHz and 58.75 MHz. True synchronous demodulation is provided with active carrier regeneration. It has a VCO frequency which ca

29、n be switchable between L and L accent (alignment external) picture carrier frequency. The TDA9818 has a SIF input for single reference QSS mode (PLL controlled). SIF AGC detector is to provide gain controlled SIF amplifier. The AM demodulator is without extra reference circuit. The supply voltage i

30、s +5VDC at pin 21. 11. COMBFILTER SAA4961 The SAA 4961 is a one-chip, PAL/NTSC combfilter IC with internal delay lines, filters, clock control, synchronisation and signal switches. The combfilter function is realised in a switched capacitor technique, so it has time discrete but amplitude continuous

31、 processing. The Y/CVBS input is first clamped and then fed to the delay-line and combfilter section via a low pass pre-filter. This filter can be bypassed via the external LPF-on pin. This pin is internally pulled up, to put the filter default on. The Y/CVBs input is also fed to the sync seperator,

32、 where horizontal and vertical reference pulses are made. Bypass mode can be forced via BYP (pin 3).FSC (pin 1) is the subcarrier input which is connected to the colour decoder. Input FSCSW pin indicates if fsc or 2*fsc is used. The Sys1,2 pins (20, 23) indicate which system standard is processed. S

33、ys2 is internally pulled up, Sys1 is internally pulled down. Therefore when the Sys1,2 inputs are left open, automatically PAL 4.43MHz is forced. SAA4961output pin 15 ?CVBS? can be used for parallel-synced teletext decoders, to guarantee that the teletext display always has a correct timing relation

34、 with the main picture. Comb filter is disabled by setting SAA4961 pin 3 ?BYP? high. 12.POWER SUPPLY (SMPS) The DC voltages required at various parts of the chassis are provided by an SMPS transformer controlled by the IC MC44604 which is designed for driving, controlling and protecting switching tr

35、ansistor of SMPS. The transformer produces 150/115V for FBT input, 14V for audio output IC, S+5V for microcontroller, +15V for vertical output (field scan) and +33V for tuner and some other ICs and transistors. 13.MICROCONTROLLER SDA525X The device is TV TEXT tuning and control system based on the S

36、DA 525X TV TEXT microcontroller. It is designed for a low cost mono TV-SET with analogue picture and sound control. Neverthless the system offers an on screen display (OSD) and IR remote control of all functions. SDA525X has the following features: - Display of program number, channel number, TV sta

37、ndard, analogue values, sleep timer, parental control, and mute is done by OSD. - Single LED for IR active, standby and on mode indication. - 1 Control line to select external source. - 3 Control lines for TV standard selection. - Frequency synthesis tuning (62.5 kHz steps) - 192 step fine tuning -

38、Channels corresponding to standards B/G, OIRT, L and I (I+) - Mono sound control by analogue voltage - System configuration with service mode 14. SERIAL ACCESS CMOS 8K (1024*8) EEPROM ST24C08 The ST24C08 is a 8Kbit electrically erasable programmable memory (EEPROM), organised as 4 blocks of 256*8 bi

39、ts. The memory is compatible with the IC standard, two wire serial interface which uses a bi-directional data bus and serial clock. The memory carries a built-in 4 bit, unique device identification code (1010) corresponding to the IC bus definition. This is used together with 1 chip enable input (E)

40、 so that up to 2*8K devices may be attached to the IC bus and selected individually. 7 15.CLASS AB STEREO HEADPHONE DRIVER TDA1308 The TDA1308 is an integrated class AB stereo headphone driver contained in a DIP8 plastic package. The device is fabricated in a 1 mm CMOS process and has been primarily

41、 developed for portable digital audio applications. 16.SAW FILTERS Saw filter type:Model: G1965M:PAL-SECAM B/G MONO G3962M:PAL-SECAM B/G GER OIRT:D/K nVoltage synthesized tuning (VST) nOff-air channels, S-cable channels and Hyperband nStandardized mechanical dimensions and pinning nCompact size PINN

42、ING PIN VALUE 1. Gain control voltage (AGC):4.0V, Max:4.5V 2. Tuning voltage 3. High band switch:5V, Min:4.75V, Max:5.5V 4. Mid band switch:5V, Min:4.75V, Max:5.5V 5. Low band switch:5V, Min:4.75V, Max:5.5V 6. Supply voltage:5V, Min:4.75V, Max:5.5V 7. Not connected 8. Not connected 9. Not connected

43、10.Symmetrical IF output 1 11. Symmetrical IF output 2 Bandswitching table: Pin 3Pin 4Pin 5 Low band 0V 0V+5V Mid band 0V+5V 0V High band+5V 0V 0V General description of UV1316: The UV1316 tuner belongs to the UV 1300 family of tuners, which are designed to meet a wide range of applications. It is a

44、 combined VHF, UHF tuner suitable for CCIR systems B/G, H, L, L?, I and I?. The low IF output impedance has been designed for direct drive of a wide variety of SAW filters with sufficient suppression of triple transient. Features of UV1316: nMember of the UV1300 family small sized UHF/VHF tuners nSy

45、stems CCIR: B/G, H, L, L?, I and I?; OIRT: D/K nDigitally controlled (PLL) tuning via I?C-bus nOff-air channels, S-cable channels and Hyperband nWorld standardized mechanical dimensions and world standard pinning nCompact size nComplies to ?CENELEC EN55020? and ?EN55013? PINNING PIN VALUE 1. Gain co

46、ntrol voltage (AGC):4.0V, Max:4.5V 2. Tuning voltage 3. IC-bus address select:Max:5.5V 4. IC-bus serial clock:Min:-0.3V, Max:5.5V 5. IC-bus serial data:Min:-0.3V, Max:5.5V 6. Not connected 7. PLL supply voltage:5.0V, Min:4.75V, Max:5.5V 8. ADC input 9. Tuner supply voltage:33V, Min:30V, Max:35V 10.S

47、ymmetrical IF output 1 11. Symmetrical IF output 2 General description of UV1336: UV1336 series is developed for reception of channels broadcast in accordance with the M, N standard. The tuning is available through built-in digitally controlled I?C bus (PLL). Features of UV1336: nGlobal standard pin

48、ning nIntegrated Mixer-Oscillator S/N:53dB, Min:47%; DC potential:2.15V, Min : 2.00V Max :2.30V 7. Input signal (from AM) to audio switch: Max:1.2V 8. Output signal from audio switch: 80dB, Min : 70dB 9. Input signal (from external) to audio switch : Max:1.2V 11 10.Switch input select control: Audio

49、 switching voltage to activate pin7 : Min :0V, Max :0.8V Audio switching voltage to activate pin9 : Min:1.5V, Max :Vp 11. Supply voltage: 12V, Min:10.8V, Max:13.2V 12.Mute control: For Mute-ON Min : 0V, Max : 0.8V For Mute-OFF Min : 1.5V, Max : Vp 13.Ground 14.Supply voltage: 5V, Min : 4.5V, Max : 8.8V 15.Not connect