Toshiba 28YT56 User manual

SERVICE MANUAL
PRINTED IN UK. 2003 C
COLOURTELEVISION
28YT56/32YT56
TOSHIBA

Service Manual
AK49-001
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TABLE OF CONTENTS
1. INTRODUCTION 4
1.1. Purpose 4
1.2. Scope 4
1.3. General Features 4
2. GENERAL DESCRIPTION 5
2.1. Introduction 5
2.2. System Building Blocks 5
2.2.1. UOC-III (Ultimate-One-Chip) 5
2.2.1.1. Fav & B_Svhs & F_Svhs 8
2.2.1.2. Scart1 8
2.2.1.3. Scart2 8
2.2.1.4. Scart3 9
2.2.1.5. VestelBus 9
2.2.1.6. Audio 9
2.2.1.7. Port Allocations 10
2.2.1.8. Power Management 11
2.2.1.9. Input & Output Performance 12
2.2.1.10. Feature Board 14
2.2.2. Audio Block 15
2.2.2.1. Audio Power Amplifier 15
2.2.2.2. Headphone Amplifier 17
2.2.2.3 Pop Noise Protection Circuit 18
2.2.3. Deflection & Display Block 19
2.2.3.1. Horizontal Deflection 19
2.2.3.2. Vertical Deflection 20
2.2.3.3. CRT Board 22
2.2.3.4. Rotation 23
2.2.3.5. X-RAY Protection 24
2.2.3.6. Dynamic Focus 24
2.2.3.7 Screen & Focus Short Circuit Protection 25
2.2.4. SMPS BLOCK 28
2.2.4.1. Primary Block 28

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2.2.4.2. Secondary Block 29
2.2.5 CABELING 31
2.2.6 CABLE SPECs 33
2.2.6.1 RGB CABLE 33
2.2.6.2 200V CABLE (with BSVM) 35
2.2.6.3 200V CABLE (with BSVM) 37
2.2.7 SAW FILTER 39
2.2.8 TUNER 40
3. AK49 CHASSIS MANUAL ADJUSTMENTS PROCEDURE 41
3.1 SMPS B+ADJUSTMENT 41
3.2 AFC ADJUSTMENT 41
3.3 FOCUS ADJUSTMENT 41
3.4 SCREEN ADJUSTMENT 42
4. AK49 CHASSIS PRODUCTION SERVICE MODE ADJUSTMENTS 43
5. MENU LANGUAGE TABLE 74
6.PICTURE MODES 75
7. CIRCUIT DIAGRAMS 79
8. APPENDIX 84
DVB-T MODUL SERVICE MANUAL

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Document History
Versi
on Date
Document
Revision and
Review
History
Status Prepared by Approved by
v0.1 14.12.2004 Draft YAVUZ İNCE
SERDAR GÜLTEN
KAGAN M. PANCAR
File Name: AK49_SM_VO1

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1. Introduction
1.1. Purpose
This document is prepared for the UOC3 TV project and describes the whole system features and
operating principles to be used in hardware design phase.
The document is based on “Device Specification UOCIII-Version 2.5” and “Introducing UOC-III” from
Philips Semiconductors.
1.2. Scope
The document covers detailed descriptions of AK49 chassis system building blocks.
1.3. General Features
AK49 is a 110°/ 50 Hz. chassis which is capable of driving CRT sizes in the range of 24” – 33”,
including realflat and 16:9 CRT’s . The chassis has the following main features;
•Remote Control
•Colour Standards ; PAL, SECAM, NTSC,
•Transmission standards ; B/G, L/L’ I/I’, DK,
•Teletex ; 10 pages,
•Intercarier/QSS sound proccessing,
•Multi-standard alignment free PLL tuning,
•PIP, PAP, POP, PAT, TAT ,
•CTI option ,
•2D Comb Filter ,2D/4H
•Headphone with volume control,
•SubWoofer option,
•2 Full Scart with SVHS availability via Scart-2 , Scart-3 / BAV, FAV and F_SVHS /B_SVHS,
•BSVM option,
•Dynamic Focus option,
•Rotation (Tilt) option,
•NICAM/GERMAN Stereo,
•Virtual Dolby option,
•2 x 10W (%10 THD),
•YPbPr input feature,
•TV-DVD Combi ,
•IDTV ,
•TV-R/HDD,
•EPG,

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2. General Description
2.1. Introduction
This chapter describes system building blocks and their detailed discriptions.
2.2. System Building Blocks
AK49 chassis main block are;
•UOC3 : Microcontroller + Video Proccessor + Sound Proccessor + IF+Teletext
•SMPS : SMPS Controller, SMT, Bridge Rect., Line Filters
•HV Block : FBT, HOT, Vertical Amplifier, Line Driver, EW Amp.
•AUDIO : Audio Amp., DAC, Comperator.
•CRT BOARD : RGB Amp.
•Feature Board : PIP, CTI IC’s.
2.2.2 UOC-III (ULTIMATE-ONE-CHIP)
UOC3 is composed of microcontroller, video proccessor, sound proccessor and IF blocks. So, there
are digital and anolog parts in it named as Picasso and Cosmic respectively as shown below ;
UOC3 has standard and face down versions, pin squence differs between two version. After
investigation of the pining it is decided to use face down version for layout compability.

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Block diagram of the TV System with face-down version is;

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?

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2.2.2.1 FAV & BAV & B_SVHS & F_SVHS
B_SVHS and F_SVHS inputs can not be supported at the same time.
FAV & B_SVHS_Y & F_SVHS_Y inputs use same CVBS input. (cvbs2/74)
B_SVHS_ C & F_SVHS_C input is C2/C3(70).
FAV audio input is AUDIOin_5 L,R (94,95) and shared with F_SVHS.
BAV video input is CVBS1 (81) and can not be supported with SCART3 at the same time.
BAV audio input is AUDIOin_4 L,R (80,79) and shared with SCART3.
2.2.2.2 SCART1
SCART1 video input is (CVBS3/71) . SCART1 video input is also applied to Video Switch
IC(TEA6415C) for PIP application.
SCART1 video out will use (IFVO/86) front_end video output, that output is also used as SCART3
video output via a buffer circuit.
SCART1 RGB/fblk inputs are R(51), G(50), B(49), FBLK(52) .
SCART1 AUDIO input is AUDIOin_3 L,R ( 73,72) .
SCART1 AUDIO output is AUDIOout_SR,SL (93,92). Same output also used as SCART3 Audio output.
2.2.2.3 SCART2
SCART2 video input is CVBS4 (78) . SCART2 video input is also applied to Video Switch IC(TEA6415C)
for PIP application.
SCART2 supports SVHS input. SVHS / C input is C4 (77) , Y input is use same video input.
SCART2 video output is CVBSO/PIP (65). That video output is selectable, all inputs can be selected to
be output from SCART2.
SCART2 RGB inputs are R(59), G(57), B(58), FBLK/INSSW2 (54), except CTI/PIP option.
At PIP application ;
-There are PIP_CVBS, SCART1, SACRT2, SCART3, FAV video inputs and RGB, FBLK inputs to PIP IC.
-If there is no CTI application, PIP output is applied to SCART2 RGB input directly.
-In case of PIP&CTI combined application, PIP output will be input to CTI IC as YUV. The YUV
output of CTI IC will be applied to R/Vin(59), G/Yin(57), B/Uin(58) as YUV.

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©Copyright 2003 VESTEL Group of Company
All rights reserved. Passing on and copying of this document, use and communication of its contents not permitted without written permission from VESTEL
YPbPr input is possible via SCART2 RGB lines with an adaptor.
In this case R/Vin(59), G/Yin(57), B/Uin(58) inputs can be used as;
-RGB,
-YUV,
-YPbPr inputs.
SCART2 audio inputs are AUDIOin_2 L,R ( 75) .
SCART2 audio outputs are AUDIOout_HPR,HPL (67,66). That output is also selectable .
2.2.2.4 SCART3
SCART3 video input is CVBS1 (81) . That input will also be used as optional BAV video input. and
applied to Video Switch IC(TEA6415C) for PIP application.
SCART3 video output will be SCART1 video output via a buffer circuit.
SCART3 audio inputs are AUDIOin_4 L,R (80,79). These audio inputs will also used for optional BAV
L,R and VESTELBUS L,R audio inputs.
SCART3 audio out will be through SCART1 audio outputs via a buffer circuit.
2.2.2.5 VESTELBUS(IDTV,DVD-Combi)
VESTELBUS video input is CVBS1 (81), so VESTELBUS will not be supported with SCART3 at the same
time.
VESTELBUS RGB inputs are SCART2 RGB inputs, so in case of VESTELBUS option SCART2 RGB
is not supported.
VESTELBUS UART input ;
- TXD TX (1),
- RXD RX (2),
- IRQ_DVB INT2 (3).
VESTELBUS I2C input is standard I2C bus.
2.2.2.6 AUDIO
Main audio out is AUDIOout_LSR,LSL (69,68).
Selectable HP out is I2SD01 24) out to DAC.
Subwoofer out is I2SD02 (25) out to DAC.