Daewoo CP-785A Schematic

S/M No. : TCP785AEF0

Service Manual

59/68 Cm STEREO Color Television

MODEL

DTE-25G5THS DTE-29G5TH

FS-59T90 FS-68T90

CHASSIS

CP-785A

DAEWOO ELECTRONICS CO., LTD.

http : //svc.dwe.co.kr NOV. 2000

Service manual CP-785A

Contents

1 - Main features ................................................................................................................................. 2

1-1 Specifications .................................................................................................................... 2

1-2 Channel table .................................................................................................................... 4

2 - Safety instruction.......................................................................................................................... 7

3 - Alignment instructions ................................................................................................................. 8

3-1 Microcontroller configuration : Service mode .................................................................... 8

3-2 Microcontroller configuration : Option................................................................................ 8

3-3 TV set Alignment............................................................................................................... 8

4 - IC description ................................................................................................................................ 10

4-1 TDA936x TV signal processor - TXT with embedded m-Controller. ..................................10

4-2 MSP3415D Multistandard Sound Processor..................................................................... 18

4-3 TDA894xJ Stereo Audio Amplifier..................................................................................... 22

4-4 TDA835xJ Vertical Amplifier.............................................................................................. 23

4-4-1 TDA8358J............................................................................................................... 24

4-5 TDA6107Q ........................................................................................................................ 25

4-6 24C08 8 Kbit EEPROM ..................................................................................................... 26

4-7 STR-F6654 ....................................................................................................................... 27

5 - Circuit description......................................................................................................................... 29

5-1 Block diagram.................................................................................................................... 29

5-2 IF ....................................................................................................................................... 33

5-3 Source switching ............................................................................................................... 34

5-4 u-Controller I/O pin configuration and function.................................................................. 34

5-5 Sound processing.............................................................................................................. 35

5-6 Sound amplification........................................................................................................... 37

5-7 Vertical deflection .............................................................................................................. 37

5-8 Power supply (STR-F6654)............................................................................................... 39

5-9 TV start-up, TV normal run and stand by mode operations ..............................................43

6 -Service parts list............................................................................................................................. 50

FS-59T90 & FS-68T90 ........................................................................................................... 50

(DTE-25G5THS & DTE-29G5TH)

7 - Exploded view ............................................................................................................................... 59

8 - PCB Layout....................................................................................................................................

9 - Circuit Diagram..............................................................................................................................

1-1 Specifications

TV standard Sound system

Power consumption

Sound Output Power

Speaker

Teletext system Aerial input Channel coverage Tuning system Visual screen size

Service manual CP-785A

PAL, SECAM - B/G, H NICAM B/G FM 2Carrier B/G 25" : 113 W approx. 29" : 118 W approx. 25" : 5W x 5W (at 60% mod, 10%THD) 29" : 5W x 5W (at 60% mod, 10%THD) 25" : 7W 8 ohm x 2 29" : 7W 8 ohm x 2 10 pages memory FASTEXT (FLOF or TOP) 75 ohm unbalanced Off-air channels, S-cable channels and hyperband frequency synthesiser tuning system 25" : 59 cm 29" : 68 cm

Channel indication Program Selection Aux. terminal

On Screen Display 100 programmes INPUT1(SCART) : Audio / Video In, S-VHS In(with cable)

INPUT2(RCA) : Audio / Video In

OUTPUT(RCA) : TV OUT Headphone jack (3.5 mm) on front of cabinet

Remote Control Unit

R-40A01 / R-44N08(RD-D90)

RCA Jack - input 2

Pin Signal Description Matching value

1 Video Input 1.0 Vpp+/- 3dB , Impedance 75 ohm 2 Audio Input Left

0.5 Vrms, Impedance > 10k ohm

3 Audio Input Right 0.5 Vrms, Impedence > 10k ohm

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Service manual CP-785A

RCA Jack output

Pin Signal Description Matching value

1 TV Video 1.0Vpp +/- 3dB , Impedence 75 ohm 2 TV Audio Left 0.5Vrms at RF sound FM 54% Mod.(27kHz dev.) 3 TV Audio Right 0.5Vrms at RF sound FM 54% Mod.(27kHz dev.)

W W

21 pin Euro SCART - Input 1 / S-Video

Pin Signal Description Matching value

1 N.C. 2 Audio Input Right 3 N.C. 4 Audio Earth 5 Earth 6 Audio Input Left 7 N.C. 8 N.C. 9 N.C. 10 N.C. 11 N.C. 12 N.C. 13 N.C 14 Earth 15 Chroma Input 16 N.C. 17 Earth 18 Video In Earth 19 N.C. 20 Video Input / Y Input 1 Vpp +/- 3dB, Impedance 75 ohm 21 Common Earth

0.5 Vrms, Impedance > 10 kW

+/- 3dB for a luminance signal of 1 Vpp

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1-2 Channel table

FREQUENCY TABLE CP-785A

CH AUSTRALIA N/Z'land C00 C01 C02 C03 C04

102.25

C05

138.25

C5A C06 C07 C08 C09 C10

216.75

C11

- 45.25

N01

- 55.25

N02

- 62.25

N03

- 203.25

N08

- 210.25

N09

- 217.25

N10

- C21 C22 C23 C24 C25 C26 C27 C28 C29 C30 C31 C32 C33 C34 C35 C36 C37 C38 C39 C40 C41

46.25

57.25

64.25

86.25

95.25

175.25

182.25

189.25

196.25

209.25

- - - -

471.25

479.25

487.25

495.25

503.25

511.25

519.25

527.25

534.25

541.25

548.25

555.25

562.25

569.25

576.25

583.25

590.25

597.25

603.25

610.25

617.25

Service manual CP-785A

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CH AUSTRALIA N/Z'land C42 C43 C44 C45 C46 C47 C48 C49 C50 C51 C52 C53 C54 C55 C56 C57 C58 C59 C60 C61 C62 C63 C64 C65 C66 C67 C68 C69

624.25

631.25

638.25

645.25

652.25

659.25

666.25

673.25

680.25

687.25

694.25

701.25

708.25

715.25

722.25

729.25

736.25

743.25

750.25

757.25

764.25

771.25

779.25

786.25

793.25

800.25

807.25

814.25

C70 - C71 - C72 - C73 C74 C75 - C76 - C77 -

S01

S02

S03

S04

S05

S06

S07

S08

S09

105.25

112.25

119.25

126.25

133.25

140.25

147.25

154.25

161.25

Service manual CP-785A

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CH AUSTRALIA N/Z'land

S10

S11

S12

S13

S14

S15

S16

S17

S18

S19

S20

S21

S22

S23

S24

S25

S26

S27

S28

S29

S30

S31

S32

S33

S34

S35

S36

S37

S38

S39

S40

S41

168.25

231.25

238.25

245.25

252.25

259.25

266.25

273.25

280.25

287.25

294.25

303.25

311.25

319.25

327.25

335.25

343.25

351.25

359.25

367.25

375.25

383.25

391.25

399.25

407.25

415.25

423.25

431.25

439.25

447.25

455.25

463.25

Service manual CP-785A

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Service manual CP-785A

2 - Safety instruction

WARNING: Only competent service personnel may carry out work involving the testing or repair of

this equipment.

X-RAY RADIATION PRECAUTION

1. Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To avoid such hazards, the high voltage must not exceed the specified limit. The nominal value of the high voltage of this receiver is 26~28 KV (25” - 29”) at max beam current. The high voltage must not under any circumstances, exceed 29.5 KV (25") or 31 KV (29"). Each time a receiver requires servicing, the high voltage should be checked. It is important to use an accurate and reliable high voltage meter.

2. The only source of X-ray Radiation in this TV receiver is the picture tube. For continued X-ray RADIATION protection, the replacement tube must be exactly the same type tube as specified in the parts list.

SAFETY PRECAUTION

1. Potentials of high voltage are present when this receiver is operating. Operation of the receiver outside the cabinet or with the back board removed involves a shock hazard from the receiver.

1) Servicing should not be attempted by anyone who is not thoroughly familiar with the

precautions necessary when working on high voltage equipment.

2) Discharge the high potential of the picture tube before handling the tube. The picture tube is highly evacuated and if broken, glass fragments will be violently expelled.

2. If any Fuse in this TV receiver is blown, replace it with the FUSE specified in the Replacement Parts List.

3. When replacing a high wattage resistor (oxide metal film resistor) in circuit board, keep the resistor 10 mm away from circuit board.

4. Keep wires away from high voltage or high temperature components.

5. This receiver must operate under AC 240 volts, 5O Hz. NEVER connect to DC supply or any other power or frequency.

PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in this equipment have special safety-related characteristics. These characteristics are often passed unnoticed by a visual inspection and the X-ray Radiation protection afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in this manual and its supplements, electrical components having such features are identified by designated symbol on the parts list. Before replacing any of these components, read the parts list in this manual carefully. The use of substitutes replacement parts which do not have the same safety characteristics as specified in the parts list may create X-ray Radiation.

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Service manual CP-785A

3 - Alignment instructions

3-1 Microcontroller configuration : Service mode To switch the TV set into service mode please see instruction below.

1 - Select pr. number 91 2 - Adjust sharpness to minimum value and exit all menu. 3 - Quickly press the key sequence : RED - GREEN - menu

To exit SERVICE menu press menu key or Operate(Std By) key.

In Service Mode press “OK” to stop the microcontroller i.e. the I2C bus is free and the set can be controlled by external equipment. Press “OK” again to allow the microcontroller to control the set again

3-2 Microcontroller configuration : Option

Option

0 DAEWOO / SAMSUNG for Daewoo Remote control 1 DAEWOO / SAMSUNG for Daewoo Remote control 4 DAEWOO / SAMSUNG for NEC Remote control 5 DAEWOO / SAMSUNG for NEC Remote control

3-3 TV set Alignment 3-3-1 - G2 alignement

- TV in AV mode without video signal ⇒ Black screen.

- TV preset with WP Red, WP Green and WP Blue equal to 32.

- TV preset with Black R, Black G equal to 8.

- Set TV in NORMAL I mode

- Adjust screen volume ( on FBT ) such that the highest cathod cut-off voltage measured on CRT

board, is Vcut off ± 5V.

3-3-2 - White balance

- Select a dark picture and adjust Black G and Black R to the desired colour temperature.

- Select a bright picture and adjust WP Red, WP Green, WP Blue to the desired colour temperature.

3-3-3 - Focus

- Adjust the Focus volume ( on FBT ) to have the best resolution on screen.

Tuner maker Remark

Screen size Vcut-off

25” 140V 29” 140V

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Service manual CP-785A

3-3-4 - Vertical geometry

- Adjust the Vertical Amplitude, Shift, S-

Correction and Slope to compensate for vertical

distortion.

3-3-5 - Horizontal picture centering

- Adjust H Shift to have the picture in the center of the screen.

3-3-6 - East / West correction

- Adjust the H Parall, H Bow, H Width, EW Parabo, Up Corner, Dw Corner, EW trapez to compensate

for geometrical distortion.

H. Parall

H. Bow

H.Width

EW.Parabola

Up Corner

Dw Corner

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Service manual CP-785A

EW Trapez

3-3-7 - AGC

- Adjust the antenna signal level at 68 dBµV± 2 (UHF - CH25)

- Set RF AGC to 0.

- Increase RF AGC level and stop when the level on pin 6 of TDA936x goes below 2.5 Vdc

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Service manual CP-785A

4 - IC description

4-1 TDA936x TV signal processor - Teletext decoder with embedded µ-Controller.

TV-signal Processor

l Multi-standard vision IF circuit with alignment-free PLL demodulator l Internal (switchable) time-constant for the IF-AGC circuit l Source selection between 'Internal' CVBS and external CVBS or Y/C signals l Integrated chrominance trap circuit l Integrated luminance delay line with adjustable delay time l Asymmetrical ‘ delay line type’ peaking in the luminance channel l Black stretching for non-standard luminance signals l lntegrated chroma band-pass filter with switchable centre frequency l Only one reference (12 MHz) crystal required for the µ-Controller, Teletext and the colour decoder l PAL / NTSC or multistandard colour decoder with automatic search system l Internal base-band delay line l RGB control circuit with 'Continuous Cathode Calibration', white point and black level off set

adjustment so that the colour temperature of the dark and the bright parts of the screen can be chosen independently.

l The Text/OSD signals are internally supplied from the -Controller/Teletext decoder

l Contrast reduction possibility during mixed-mode of OSD and Text signals l Horizontal synchronisation with two control loops and alignment-free horizontal oscillator l Vertical count-down circuit l Vertical driver optimised for DC-coupled vertical output stages l Horizontal and vertical geometry processing l Horizontal and vertical zoom function for 16 : 9 applications l Horizontal parallelogram and bow correction for large screen picture tubes

-Controller

l 80C51 µ-controller core standard instruction set and timing l 1µs machine cycle l 32 - 128Kx8-bit late programmed ROM l 3 - 12Kx8-bit Auxiliary RAM (shared with Display and Acquisition) l Interrupt controller for individual enable/disable with two level priority l Two 16-bit Timer/Counter registers l WatchDog timer l Auxiliary RAM page pointer l 16-bit Data pointer l IDLE and Power Down (PD) mode l 14 bits PWM for Voltage Synthesis Tuning l 8-bit A/D converter l 4 pins which can be programmed as general I/0 pin, ADC input or PWM (6-bit) output

Data Capture

l Text memory 10 pages

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Service manual CP-785A

l Inventory of transmitted Teletext pages stored in the Transmitted Page Table (TPT) and Subtitle Page Table (SPT)

l Data Capture for US Closed Caption l Data Capture for 525/625 line WST, VPS (PDC system A) and Wide Screen Signalling (WSS) bit

decoding Automatic selection between 525 WST/625 WST

l Automatic selection between 625 WST/VPS on line 16 of VBI l Real-time capture and decoding for WST Teletext in Hardware, to enable optimised µ-processor

throughput

l Automatic detection of FASTEXT transmission l Real-time packet 26 engine in Hardware for processing accented, G2 and G3 characters l Signal quality detector for video and WST/VPS data types l Comprehensive teletext language coverage l Full Field and Vertical Blanking lnterval (VBI) data capture of WST data

Display

l Teletext and Enhanced OSD modes l Features of lever 1.5 WST and US Close Caption l Serial and Parallel Display Attributes l Single/Double/Quadruple Width and Height for characters l Scrolling of display region l Variable flash rate controlled by software l Enhanced display features including overlining, underlining and italics l Soft colours using CLUT with 4096 colour palette l Globally selectable scan lines per row (9/10/13/16) and character matrix [12x10, 12xl3, 12x16

(VxH)]

l Fringing (Shadow) selectable from N-S-E-W direction l Fringe colour selectable l Meshing of defined area l Contrast reduction of defined area l Cursor l Special Graphics Characters with two planes, allowing four colours per character l 32 software redefinable On-Screen display characters l 4 WST Character sets (GO/G2) in single device (e.g. Latin, Cyrillic, Greek, Arabic) l G1 Mosaic graphics, Limited G3 Line drawing characters l WST Character sets and Closed Caption Character set in single device

Data Capture

The Data Capture section takes in the analogue Composite Vidéo and Blanking Signal (CVBS), and from this extracts the required data, which is then decoded and stored in memory.

The extraction of the data is performed in the digital domain. The first stage is to convert the analogue CVBS signal into a digital form. This is done using an ADC sampling at 12MHz. The data and clock recovery is then performed by a Multi-Rate Video Input Processor (MuIVIP). From the recovered data and clock the following data types are extracted WST Teletext (625/525), Closed Caption, VPS, WSS. The extracted data is stored in either memory (DRAM) via the Memory Interface or in SFR locations.

Data Capture Features

- Video Signal Quality detector

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Service manual CP-785A

- Data Capture for 625 line WST

- Data Capture for 525 line WST

- Data Capture for US Closed Caption

- Data Capture for VPS data (PDC system A)

- Data Capture for Wide Screen Signalling (WSS) bit decoding

- Automatic selection between 525 WST/625WST

- Automatic selection between 625WST/VPS on line 16 of VBI

- Real-time capture and decoding for WST Teletext in Hardware, to enable optimised microprocessor throughput

- 10 pages stored On-Chip

- lnventory of transmitted Teletext pages stored in the Transmitted Page Table (TPT) and Subtitle Page Table (SPT)

- Automatic detection of FASTEXT transmission

- Real-time packet 26 engine in Hardware for processing accented, G2 and G3 characters

- Signal quality detector for WST/VPS data types

- Comprehensive Teletext language coverage

- Full Field and Vertical Blanking Interval (VBI) data capture of WST data

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Service manual CP-785A

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Service manual CP-785A

Chassis IC marking

OSD languages Capacity Text

CP-785A DW9365/N1/3-BDx

(OTP: TDA9365PS/

English

64K Pan-European, 10 pages Teletext

N1/5S

PINNING

SYMBOL PIN DESCRIPTION

n.u. 1 Port 1.3 Not used. SCL 2 I2C bus clock line SDA 3 I2C Data line SECAM L’ out 4 Port 2.0 : High when L’ selected (PushPull ) OCP 5 Port 3.0 : Over Current Protection RF AGC in 6 ADC 1 : For factory use only ( High impedance ) Key-in 7 ADC 2 : local key input ( High impedance ) S/SW 8 ADC 3 : Scart Slow switching input VssC/P 9

digital ground for µ-controller core and peripheral

LED 1 10 port 0.5 ( 8mA current sinking capability ) LED 2 11 port 0.6 ( 8mA current sinking capability ) VSSA 12 analog ground of teletext decoder and digital ground of TV processor SEC PLL 13 SECAM PLL decoupling VP2 14 2nd supply voltage TV-processor DECDIG 15 decoupling digital supply of TV-processor PH2LF 16 phase-2 filter PH1LF 17 phase-1 filter GND3 18 ground 3 for TV-processor DECBG 19 bandgap decoupling AVL/EWD 20 East / West drive output VDRB 21 vertical drive B output VDRA 22 vertical drive A output IFIN1 23 IF input 1 IFIN2 24 IF input 2 IREF 25 reference current input VSC 26 vertical sawtooth capacitor TUNERAGC 27 tuner AGC output SIFIN1 28 SIF input 1 SIFIN2 29 SIF input 2 GND2 30 ground 2 for TV processor SIF AGC 31 AGC sound IF REF0 32 n.u. HOUT 33 horizontal output FBISO 34 flyback input / sandcastle output

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Service manual CP-785A

SYMBOL PIN DESCRIPTION

QSS out 35 QSS intercarrier output EHT0 36 EHT/Overvoltage protection PLLIF 37 IF PLL loop filter IFVO 38 IF video output VP1 39 main supply voltage TV-processor CVBSINT 40 internal CVBS input GND1 41 ground 1 for TV-processor CVBS/Y 42 external CVBS/Y input CHROMA 43 chrominance input (SVHS) AMOUT 44 n.u. INSSW2 45 2nd RGB insertion input R2IN 46 2nd R input G2IN 47 2nd G input B2IN 48 2nd B input BCLIN 49 beam current limiter input BLKIN 50 black current input R0 51 RED Output G0 52 GREEN Output B0 53 BLUE Output VDDA 54 analog supply of Teletext decoder and digital supply of TV-Processor

(3.3V) VPE 55 OTP programming supply VDDC 56 digital supply to core (3.3V) OSCGND 57 oscillator ground supply XTALIN 58 crystal oscillator input XTALOUT 59 crystal oscillator output RESET 60 reset VDDP 61 digital supply to periphery (3.3V) Audio Mute 62 Port 1.0 : Audio mute output (PushPull ) Power 63 Port 1.1 : Power output (PushPull ) IR in 64 Interrupt input 0 : R/C Infrared input

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Service manual CP-785A

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Service manual CP-785A

4-2 MSP3415D Multistandard Sound Processor The MSP 3415D is designed as a single-chip Multistandard Sound Processor for applications in analogue and digital TV sets, video recorders, and PC cards.

MSP 3415D features

- sound IF input

- No external filters required

- Stereo baseband input via integrated AD converters

- Two pairs of DA converters

- Two carrier FM or NICAM processing

- AVC : Automatic Volume Correction

- Bass, treble, volume processing

- Full SCART in/out matrix without restrictions

- Improved FM-identification

- Demodulator short programming

- Autodetection for terrestrial TV - sound standards

- Precise bit-error rate indication

- Automatic switching from NICAM to FM/AM or vice versa

- Improved NICAM synchronisation algorithm

- Improved carrier mute algorithm

- Improved AM-demodulation

- Reduction of necessary controlling

- Less external components

Basic Features of the MSP 3415D

Demodulator and NICAM Decoder Section

The MSP 3415D is designed to simultaneously perform digital demodulation and decoding of NICAMcoded TV stereo sound, as well as demodulation of FM or AM mono TV sound. Alternatively, two carrier FM systems according to the German terrestrial specs can be processed with the MSP 3415D.

The MSP 3415D facilitates profitable multistandard capability, offering the following advantages:

- Automatic Gain Control (AGC) for analogue input: input range: 0.10 - 3 Vpp

- integrated A/D converter for sound-IF input

- all demodulation and filtering is performed on chip and is individually programmable

- easy realisation of all digital NICAM standards (B/G, I, L and D/K)

- FM-demodulation of all terrestrial standards (include identification decoding)

- no external filter hardware is required

- only one crystal clock (18.432 MHz) is necessary

- high deviation FM-mono mode (max. deviation: approx. ± 360 kHz)

DSP-Section (Audio Baseband Processing)

- flexible selection of audio sources to be processed

- performance of terrestrial de-emphasise systems (FM, NICAM)

- digitally performed FM-identification decoding and de-matrixing

- digital baseband processing: volume, bass, treble

- simple controlling of volume, bass, treble

Analogue Section

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