Toshiba Color Television

TOSHIBA COLOR TELEVISION

NTSC SYSTEM

SERVICE MANUAL

CHASSIS NO.T08

CONTENTS

一、Brief Introduction

二、ELECTRICAL SPECIFICATIONS

三、Structure Block Diagram

四、Definition & Function of TMPA8873-XXXX Pins

五、Remote control（key assignments list）

六、Circuit Analysis

七、Main ICs Introduction

八、Descriptions for the operation of factory mode

一、Brief Introduction

TOSHIBA TMPA8873-XXXX is introduced in this chassis, controlled by I2C bus, implement FS PLL tuning.

1、FS tuning 45.75M. band adjustable

2、tuning in USA channel table by CATV/antenna.

3、Auto tuning, frequency fine tuning, skip setting

4、Color Sys: PAL-M\ PAL-N\ NTSC-M auto identified

5、2 AV input, YUV input, AV1\AV2\DVD(YUV) input preset

6、Switch program by numeric key directly,

7、Picture mode: personal\dynamic\standard\soft, switched by one key

8、Picture parameters adjustment: brightness\contrast\color\ sharpness\hue

9、Mute control: mute when switch programs and AV

10、Power on/off timer, program timer

11、Auto power off 15 minutes later when no signal in TV mode

12、special halftone menu display

13、English\French\Spanish\Portuguese menu display

14、8 self-detect signals generated by CPU for geometry distortion adjustment

15、50HZ/60HZ auto identified

16、Child lock(by press DISP button 4 seconds)

17、AV stereo, 2 volume inner control

18、Color and vertical position of main menu variable

19、Factory logo setting when no signal

20、TA1304/TA1343 tone control Plug-and-Play(25”~34”)

22、Multifunctional RC unit（LA7461、TA9028、SC6122）may be efficiency or only one be efficiency

二、ELECTRICAL SPECIFICATIONS

Model Number
RF system / PAL-M/N 、NTSC-M
Video system / PAL-M/N 、NTSC-M
Receiving
channel / AIR
CATV（STD）
CATV（HRC）
CATV（IRC）
Channels preset / 181
Antenna input / 75 Ohm Coaxial Cable
Picture tube / 37cm~86cm(14”~34”) diagonal
Audio output / 14” 、 21”: Maximum 2.5W×2
25” 、 29”、34”: Maximum 5W×2
Power source / AC90V~260V（OR AC130~260V）50/60Hz
Weight(Approx) / 14”(11Kg), 21”(24Kg), 25”(30Kg),29”(38Kg)
Dimensions
(W×H×D) (Approx) / 14” 450(W)×410(D)×378(H)mm
21” 580(W)×515(D)×520(H)mm
25” 750(W)×528(D)×560(H)mm
29” 840(W)×570(D)×650(H)mm
Power Consumption / 14”=65W 21”=75W 25”=120W
29”=130W 34”=150W

Designs and specifications are subject to change without notice.

WARNING

The chassis in this receiver is partially hot. Use an isolation transformer between the line cord plug and power receptacle, when servicing this chassis. To prevent electric shock, do not remove cover.

No user-serviceable parts inside. Refer servicing to qualified service personnel.

三、Structure Block Diagram

AV1

AV2

TDA7266

A1 A2

S-AV y

Video Audio

S Y Cb Cr CRT

四、TMPA8873-XXXX Block Diagram：

TMPA8873-XXXX：

①CPU part：

item / definition / description
1 / DVD / high level output in DVD mode
2 / NO USE
3 / KEY / Control signal input; TOSHIBA and SANYO general keyboard circuit auto identified
4 / GND / MCU GND
5 / REST / MCU reset when power on
6 / X-TAC / Connect ports for crystal; 20PPM precision required
7 / X-TAC
8 / TEST / For MCU experimentation, connected to GND normal
9 / 5V / Power input for CCD amplitude restricted circuit
10 / Vss / GND for CCD amplitude restricted circuit
54 / GND / GND for surgecircuit
55 / 5V / Power for surge circuit;
Duty cycle and Ripple voltage less than 10 mV;
56 / AV SW / Multi-control level output 2 or 3 TV/AV mode
57 / SDA / SDA input
58 / SOL / SCL input
59 / 50/60HZ / Low level when 50HZ
High level when 60HZ
60 / NO USE
61 / MUTE / MUTE control
62 / NO USE
63 / RMT IN / RC unit signal input
64 / Power / Power control; low level for initialization; related with item ONTIME of Page F11

Note for control port output state: (in the output table below,”0”for low level, “1” for high level)

Pin3 Description:

Voltage range for each button (middle value is suggested)

KEY / Off / P+ / P- / V+ / V- / MENU / TV/AV / POWER
Range(Sanyo) / 0V / ≤1.16V / ≤1.74V / ≤2.45V / ≤3.17V / ≤3.88V / ≤4.60V / ≤5V
Range (Toshiba) / 5V / 0≤0.45V / ≤1.02V / ≤1.74V / ≤2.45V / ≤3.17V / ≤3.88V / ≤4.60V

Pin6、Pin7 less than 20PPM precision required for crystal

Duty cycle and Ripple voltage of power for Pin55 must less than 10 mV;

(power for OSD clock)

Pin56 AV/TV switch

TV / AV1/S/DVD / AV2 / Connect way
OPT.2=0 / 0V / 0V / 5V / Pull up resistance connected to 5V or 8V
OPT.2=1;OPT.5=0 / 0V / 2.5V / 5V / 10K pull up resistance connected to 5V and 10K pull down resistance connected to GND
OPT.2=1;OPT.5=1 / 0V / 5V / 2.5V / 10K pull up resistance connected to 5V and 10K pull down resistance connected to GND

Pin59 50HZ/60HZ switch

Pin59 / NTSC(60HZ) / PAL(50HZ)
voltage / 5V / 0V

Pin61 Mute 1K pull up resistance

Pin64 Power

a)RC, Pin61\64 wave:

Mute setting

MODE2.0 / 0 / Not mute in no signal TV mode when no blue background,
1 / Mute in no signal TV mode when no blue background
MODE2.1 / 0 / Mute in no signal AV mode when no blue background
1 / Not mute in no signal AV mode when no blue background

②Signal transacting part:

11 / TV GND / Analog GND
12 / FBP-IN / Input port for flyback pulse
13 / H-out / Output port for horizontal driver pulse
14 / H-AFC / Connect port for horizontal AFC filter
The voltage of this port control the frequency of H-VCO
15 / V-SAW / Connect capacitor for SAW generating,
The amplitude of SAW is a constant because of the controlling of V-AGC
16 / V-out / Vertical driver pulse output
17 / H-Vcc / 8V power for deflection
18 / TV GND / Analog GND
19 / Cb / Input port for Cb signal
20 / Y-IN / Input port for Y signal
21 / Cr / Input port for Cr signal
22 / EXT-AU1 / AUDEO1 input
23 / C-in / Input port for C signal
24 / V2 / Input port for CVBS/Y signal
25 / ACL / Interface for ACL filter
26 / TV-in / Input port for TV video signal
27 / ABC-in / ABCL input
28 / Audio-out1 / Port 1 for audio output with volume control function
29 / Audio-out2 / Port 2 for audio output with volume control function
30 / TV-out / PIF demodulation signal(full TV signal) output
31 / SIF / Sound intermediate frequency output(may no periphery circuit)
32 / EXT-AU2 / AUDEO2 input
33 / SIF in / Second sound intermediate frequency or horizontal phase emendation signal input
34 / DC NF / Connect with capacitor
35 / PIF•PLL / Connect with PIF-PLL filter
36 / IF-5V / 5V power for IF
37 / S-Reg / Connected with filter capacitor, stabilization inner bias
38 / AU OUT / Audio output, not with volume control
39 / IF AGC / Connected with AGC filter
40 / IF GND / IF GND
41 / IF in / Pin41、Pin42 are input port for differential amplifier, input IF signal from SAW
42 / IF in
43 / RF AGC / RF-AGC signal output for tuner
44 / Black Det / Connected with black detect filter
45 / Monitor out / CVBS/SVM output, CVBS/SVM selected by I²C
46 / APC fil / Connected with APC filter of chroma decode circuit
47 / YC VCC5V1 / Power for YC
48 / SYNC OUT / SYNC output
49 / DVCC—3.3V / Power for digital circuit
50 / R out / R output
51 / G out / G output
52 / B out / B output
53 / GND / Connected with analog GND

五、Remote control（key assignments list）：

ico / function / data (D7-D0) / 9028-0E0E
H E X / LC6122
BF40 / 7461-54H7
H E X / 7461-55K2
H E X
1 / Number key / 00000000 / 00 / 00 / 1 / 1
2 / 00000001 / 01 / 01 / 2 / 2
3 / 00000010 / 02 / 02 / 3 / 3
4 / 00000011 / 03 / 03 / 4 / 4
5 / 00000100 / 04 / 04 / 5 / 5
6 / 00000101 / 05 / 05 / 6 / 6
7 / 00000110 / 06 / 06 / 7 / 7
8 / 00000111 / 07 / 07 / 8 / 8
9 / 00001000 / 08 / 08 / 9 / 9
0 / 00001001 / 09 / 09 / 0 / 0
-/-- / 00001010 / 0A / 0A / 0a / 0a
POWER / Standby key / 00001011 / 0B / 0B / 0x12 / 0x1C
BTSC / BTSC key / 00001100 / 0C / 0C / 0x1f / 0x0d
P.P / Picture mode key / 00001110 / 0E / 0E / 0x19 / 0x13
TV/AV / TV/AV key / 00001111 / 0F / 0F / 0x0B / 0x0f
P- / Channel lessen key / 00010000 / 10 / 10 / 0x17 / 0x1a
P+ / Channel add key / 00010001 / 11 / 11 / 0x13 / 0x1b
Vol- / Volume lessen key / 00010010 / 12 / 12 / 0x14 / 0x1e
Vol+ / Volume add kye / 00010011 / 13 / 13 / 0x10 / 0x1f
MUTE / Mute key / 00010100 / 14 / 14 / 0x16 / 0x15
SLEEP / Sleep key / 00010101 / 15 / 15 / 0x0f / 0x19
DISP/LOCK / Display/lock key / 00010110 / 16 / 16 / 0x1b / 0x14
RECALL / RECALL key / 00010111 / 17 / 17 / 0x1a / 0x0e
MENU / Menu key / 00011100 / 1C / 1C / 0x0e / 0x10
PIC / Picture menu key / 0001101 / 1D / 1D / 0x1c / 0x0c
SOUND-MODE / SOUND-MODE key / 00011110 / 1E / 1E / 0x1d / 0b
D-MODE / Factory key / 00101100 / 2C / 2C / 0x11 / 0x1d

六、Circuit Analysis

1．tuning circuit：

Buildup by frequency synthesized, PLL tuning, controlled by I2C bus tuner and some individual components. Tuning process controlled by correlation pins of UOC TMPA8873-XXXX. Pin57 & pin58 of CPU output I2C tuning data for SCL & SDA of tuner.

FS tuner introduced in this chassis, cooperate with SCL & SDA data from pin57 & pin58 of N101, processing FS auto tuning. 33V for tuner supplied by 110V(130V), divided by R518 and stabilized voltage by N505.

Frequency synthesized fashion is also called PLL frequency synthesized fashion. It is the CPU controlled by channel subscribe program、band switch and data from RC receiver and give the band switch signal. CPU set frequency divide ratio for variable frequency divider of PLL. Variable frequency divider dividing the local oscillation frequency from tuner and compare the phase with benchmark frequency, adjust local oscillation frequency accord with the local oscillation frequency needed by each channel.

2、Picture IF circuit：

The IF signal from tuner enter into SAW filter Z101(F45C/SW05) after amplified by Pre-Amp built up by V103 and so forth, filtered accordance with IF characteristic and enter into pin41 & pin42 of N101 at last. The purpose of add Pre-Amp is to compensate the inset loss of SAW filter and advance SNR.

The IF signal be amplified and video frequency demodulated after enter TMPA8873-XXXX and output PIF demodulation signal(CVBS) from pin30, pass through the emitter follower buildup by R155、R156、V104、R158, coupled to pin26 (inner switch)of TMPA8873-XXXX by C147.

3、sound processing：

The SIF2, come from inner phase lock demodulate of TMPA8873-XXXX, turned into audio signal after limiting amplifier and frequency discriminator. Two audio signal, out of pin28 & pin29 of TMPA8873-XXXX, enter pin4、pin12 of N601 separated and audio power amplified.

4、periphery AV input processing：

Periphery AV1（V1、L1、R1）input from pin5、pin 12、pin 2 of N801（TC4053）separated. Periphery AV2（V2、L2、R2）input from pin3、pin 13、pin1 of N801（TC4053）separated. The level output from pin56 of N103 control the switch of N801. The video signal, output from pin4 of N801, transmitted to inner of TMPA8873-XXXX by pin24 of N101 after switched. The audio signal, output from pin14 & pin15 of N801, transmitted to inner of TMPA8873-XXXX by pin24 of N101.

5、line scan：

Inner synchronize separate included in TMPA8873-XXXX, build up by VCO surge circuit, line frequency divider, AFC circuit, line output driver. Line driver signal output from pin13 of TMPA8873-XXX, amplified by V431 (2SC2383) at line-excited level and then amplified by V432 at line output level.

T471 is the FBT. Volts d.c. +110V（21”）+135V（29”）enter it through pin4. Line flyback pulse divided into two routes: one for heater (virtual value 6.3V) and one for FBP of AFC after through R405 and stabilized voltage by VD408 (9.1V). Pulse output from pin10 of T471 rectified by VD447 and filter by C447 and we get +180V for Pre-Amp as power supply. Pin9 of FBT is ABL , used as input of pin27 of TMPA8873-XXXX.

6、field scan：

Field output level buildup by CD78040/LA78041(N451) and its periphery components.

Field synchronization signal enter into saw wave produce circuit after synchronization separate. Pin16 of TMPA8873-XXXX output field saw wave driver signal to pin1 of CD78040/LA78041by pass R451, and it is output from pin5 after driver amplified and output power amplified at the inner of CD78040/LA78041(N451). C450、R454、R453、R461A/B are field feedback components for improving filed linearity and stabilizing the field work point. Field feedback signal enter pin7 of LA7841. VD451、C451 buildup a bootstrap rise voltage circuit. The power supply for pin6 of LA7841 is 26V during scan time and bootstrap rise voltage to 48V during flyback time. In this way, the work efficiency of field output level is improved and also the voltage of power supply for pin7 will not less than the pulse amplitude of pin5 during flyback, and eliminate retrace efficiency accordingly. By the way, if the linearity of scan is not well, it is something wrong with bootstrap rise voltage circuit commonly.

7、H-PARAB emendation circuit:

The principle of H-PARAB emendation is to using field parabolical wave to modulating amplitude of horizontal scan current. The current accretion according to parabolical wave rule during electron beam scan the middle of screen and so on the H-PARAB raster turned into rectangle raster.

8、color driver：

Tricolor signal amplified by tricolor driver. The white balance adjustment of this chassis completed under the control of I2C bus.

9、power supply：

1、A3 power supply: The power supply of this chassis adopt self-excitation pulse transformer coupling switch power. It’s very steady because of the photo-electricitytransfer component adopted for stabilized voltage sampling.

1）power supply analyses：

A、Rectifying：

A.C. 220V is delivered to bridge rectifier circuit buildup by VD503~VD506 after filted by noise filter composed by L501、R501、C501、C502, and transformed to 300V D.D. voltage after filted by L502、C507 and powered supply for collector of V513 by elementary coil of switch mode transformer T511.

B、oscillator circuit：

Self-excitationoscillator circuitbuildup by switch transistor V513 and switch-mode transformer T511, and the error sampling circuit buildup by R552~R554、RP551、VD560、V533、N501.

C、stabilized voltage：

Photo coupler N501 buildup by a LED and a photo trail-transistor. The work state of photo trail-transistor controlled by the light emitted by LED. The voltage controlling LED get from 110V/130V by sampling circuit buildup by R552~R554、RP551、VD560、V553. The voltage from collector of V553, connected with the LED negative inner N501,controlling the light emitted by LED.

D、Rectifier and Filter Circuit：

Switch-mode transformer T511 supply different working voltage for chassis by its 4 secondary windings and separate the power supply of chassis from mains supply..

2、WIDE POWER（90V~260V）IC-W65XX Introduction：

A、W65XX Block diagram(Connection diagram)：

B、Functions of Each Terminal：

Terminal No. / Symbols / Descriptions / Functions
1 / D / Drain terminal / MOSFET Drain
2 / — / — / —
3 / S/GND / Source and Ground terminal / MOSFET Source and Ground
4 / VCC / Power supply terminal / Input of power supply for control circuit
5 / SS/ADJ / Soft-Start and Over-current protection adjustment Terminal / Adjustment of over-current protection and Soft Start Operation Time set up
6 / FB / Feed back terminal / Constant Voltage Control Signal Input and Burst(intermittent)mode Oscillation Control
7 / BD / Bottom Detection Terminal / Bottom Detection Signal Input and External Latch Signal Input

七、The T08 chassis mainly use the following IC and assemblies

1、14~21”(AC90~260V)

NO. / Position / Type / Function Description
1 / N101 / 8873CPCNGXXX / Controller and small signal processor
2 / N102 / 24C08 / EEPROM
3 / N801 / HM14053N / Analog switch
4 / N451 / CD78040/LA78040 / Vertical scan output stage circuit
5 / N601 / TDA7266 / Audio processor
6 / N502 / STR-W6553A / Power supply circuit
7 / TU201 / ET-5C511-M04 / Tuner

2、25~34”(AC90~260V)

NO. / Position / Type / Function Description
1 / N101 / 8873CPCNGXXX / Controller and small signal processor
2 / N102 / 24C08 / EEPROM
3 / N801 / HM14053N / Analog switch
4 / N451 / LA78041/STV8172 / Vertical scan output stage circuit
5 / N601 / TDA7266 / Audio Amplifier
6 / N502 / STR-W6556A / Power supply circuit
7 / TU201 / ET-5C511-M04 / Tuner

八、Descriptions for the operation offactory mode：

1、Enter/exit factory mode

A. 1) Use factory remote control to enter factory mode

Use factory remote control:

Press FA key (Factory key) once to enter the factory debugging menu directly.

2) Use user remote control to enter factory mode

In TV state, press the “Menu” key, the main menu appears, then press the number keys “2”, “4”, “8” and “3”.

Note: stop 2 to 3 seconds between “4” and “8”.

B. Method to return to the factory mode

A. User remote control:

1) Press DISP to directly return to the factory debugging menu.

2) Press the power key to return to the factory state. When start again, the device retains the factory mode.

B. Use factory debugging remote control:

1) Press FA key (Factory key) to return to the factory debugging menu.

C. Aging mode

a. Use factory debugging remote control:

1) Press FA key (Factory key) twice to enter the aging mode, the screen displays “factory”.

b. Manual operation:

1) In the factory debugging menu, press power switch to exit the factory debugging state. When start again, the device retains the factory mode.

Note:

Press “Menu” and then “Audio mode” in the factory mode or the aging mode to directly adjust data, and the screen displays corresponding menu + factory. Press “Menu” to display the main menu adjustment data. All analog volumes have step of 50 and program searching speed doubles. To exit data debugging, press DISP, the screen displays “factory” only.

2. White balance debugging:

1)Intensifying ring adjustment: enter the factory debugging menu and press ”--/-” key to show a horizontal bright line, adjust the bright line to make it just visible, then the adjustment is completed. Press ”--/-” key to quit the bright line.

2)Manual white balance adjustment: Press the Factory key of the remote control to enter the factory debugging menu, press Mute or Recall key or directly press Number key “2” to select F2 settings page. Press P+/P- to select setting options and V+/V- key to adjust setting values.

Short-cut keys for manual white balance adjustment under horizontal bright line:

“Number key 1 and 4”: adjust red bias;

“Number key 2 and 5”: adjust green bias;

“Number key 3 and 6”: adjust blue bias.

3) Use automatic white balance meter to adjust white balance:

Debugging interface: XS102-WB (5V, GND, SCL, SDA)

Bus release: Press the Factory key to enter the factory debugging menu, press “SLEEP” key, the CPU releases the bus control right to the automatic white balance meter, then the screen displays “TV IC ADJUST”. After the adjustment is completed, press “SLEEP” key to return to the factory mode, press the “Factory” key once again to return to normal mode.

Corresponding memory address of 24C08 and 8873-NTSC

Decoding address / Memory address
R cut off / 8（8） / 30（48）
G cut off / 9（9） / 31（49）
B cut off / A（10） / 32（50）
R Drive
G Drive / B（11） / 33（51）
B Drive / C（12） / 34（52）
Slave / 88（136） / A0（160）

Note: if the value is not available, set as ______, the cancel range is ______.

Note: shortcut keys for factory debugging

After entering the factory mode, functions of some keys of the remote control will change to meet the production and debugging needs.

1) Press the mute key to turn the debugging page in forward direction and press Back key to turn the debugging page in backward direction.

2) Press “CH+” and “CH-” on the remote control to select menu options and press “VOL+” and “VOL-” to change setting values.

3) Press “TV/AV” to display 4 testing signals of the chip:

Black field:See the dark balance.

White field:See the bright balance.

Cross: Adjust the central value of the line field.

Square: Adjust linearity and line field amplitude. It is desired that edges of the square are just invisible.

3. Setting menu description of item F0~F5 of factory debugging:

F0：NTSC system geometry adjustment (No adjustment can be made for the PAL system)

Item / Descriptions / Recommend Data / Max

NT.H.PHASE

60Hz line center setting

13

31 NT.V.POSI

60Hz field center setting

5

15

NT.V.SISE

60Hz field amplitude setting

NT.V.LIN

60Hz linearity setting

NT.V.SC

60Hz field S correction

NT.HBOW

Bow correction

NT.HPARA

Parallelogram correction

H.BLK.LEFT

Line left black

H.BLK.RIGHT

Line right black

F1：PALsystem geometry adjustment (deviation relative to NTSC value) (adjustment can only be made under PAL signal)

Item / Descriptions / Recommend Data / Max

H.PHASE

50Hz line center setting

-11~10

V.POSITION

50Hz field center setting

-11~10

V.SIZE

50Hz field amplitude setting

-11~10

V.LIN

50Hz linearity setting

-11~10

V.SC

50Hzfield S correction

-11~10

HBOW

Bow correction

-8~07

HPARA

Parallelogram correction

-8~07

F2：Brightness balance adjustment

Item / Descriptions / Recommend Data / Max

Red cut-off voltage setting

110

255

Green cut-off voltage setting

110

255

Blue cut-off voltage setting

110

255

Green driving gain setting