Akai 21CT06FS Schematic

COLOUR TV SET

Models:

www.akai.ru

1 Technology Specification and Feature

2. The survey

Table 1, the main IC and functions

Number Function IC Remark

1 Power supply KA5Q0765RT N501

2 CPU + SIGNAL PROCESSER TDA93x1 N301

3 Field driver LA78040/STV9302A N401

4 Sound processor TDA9859 N122

5 Sound driver AN17821A N161

6 AV SWITCH TC4052BP N801 (Video)

7 Memory AT24C08 N702

8 Photo-coupler HS817B N504

9 IR-receiver HS0038A U701

10 8V Regulator L7808CV N503

11 5V Regulator L7805CV N505

3. The main chips instruction

1

. TDA93X1

T

he UOC (“Ultimate One Chip”) TDA93X1

is adopted in this chassis. This IC is the first available component that contains the complete

c

ontrol and small signal functionality needed for a TV application in one device.

T

he UOC TDA93X1 pins function description：（total 64 pins）

Pin1: Standby control,“ 1” is on,“ 0” is off.

Pin2: SCL.

Pin3: SDA.

Pin4: Tuning PWM output.

Pin5: Auto AV control SW/NTSC SW,

Pin6: Key board input.

Pin7: Volume

Pin8: Mute control,“ 1” is mute,“ 0” is off.

Pin9: Pin12、Pin18、Pin30、Pin35、Pin41、Pin55: GND.

Pin10: BAND1 control output.

Pin11: BAND2

Pin12: GND

Pin13: SECAM PLL, connected with a capacitance.

2

Pin14: +8V power source supply.

Pin15: Using a capacitor of 220n in series to GND, This pin decouples the internal digital supply

v

oltage of the video processor and minimizes the disturbance to the sensitive analogue parts.

Pin16: PHI-2 control loop, this pin requires a capacitor at 2.2nF (C) in series to GND.

Pin17: PHI-1 control loop, the loop filter connected to pin 17 is suitable for various signal conditions

li

ke strong/weak and VCR signal. This is achieved by switching of the loop filter time constant

b

y changing the PHI-1 output current.

Pin18: GND.

Pin19: Bandgap decoupling, the bandgap circuit provides a very stable and temperature independent

re

ference voltage. This reference voltage (4.0 V) ensures optimal performance of the analogue

v

ideo processor part of the N301 and is used in almost all functional circuit blocks.

Pin20: East-west pillow signal output.

Pin21: Pin22：Vertical drive output.

Pin23: Pin24：IF input。

Pin25: Reference current, This pin requires a resistor to ground. The optimal reference current is

100mA which is determined by this resistor. The 100mA reference current should not be changed

b

ecause the geometry processor is optimised for this current. Furthermore the output current of

v

ertical drive and EW are proportional to this current.

Pin26: Vertical sawtooth, This pin requires a capacitor to ground of 100nF

Pin27: AGC output. This output is used to control (reduce) the tuner gain for strong RF signals.

Pin28: Audio de-emphasis.

Pin29: Sound decoupling. This pin requires a capacitor connected to ground. The pin acts as a low

p

ass filter needed for the DC feedback loop.

Pin30: GND.

Pin31: Sound loop filter.

Pin32: AVL filter.

Pin33: Horizontal drive signal output, needs a resistor in series to +8V.

Pin34: Sandcastle output/flyback input,

Pin35: External audio input, this pin should be grounded in this chassis.

Pin36: EHT tracking/ overvoltage protection. If something is wrong, the anode high voltage rises, the

h

eater voltage will rise too. When the rising voltage arrive some limit, the VD461 works, the

v

oltage of pin 36 will exceed 3.9V, the N301will stop working.

Pin37: PLL loop filter.

Pin38: CVBS output. Monitor or RF videos can be selected.

3

Pin39: +8V supply source.

Pin40: CVBS input

Pin42: Y signal input.

Pin43: C signal input.

Pin44: Main audio output

Pin45: RGB signal input blanking.

Pin46, Pin47, Pin48: RGB signal input.

Pin49: ABL. It means been current limiter input. The R464 is the control resister.

Pin50: Black current input from the CRT board.

Pin51, Pin52, Pin53: RGB drive signal output to the CRT board.

Pin54: +3.3V.

Pin55: GND.

Pin56: +3.3V.

Pin57, Pin58, Pin59: 12MHz crystal。

Pin60: Reset, NC in this chassis.

Pin61: +3.3V

Pin62: This pin is connected to the HEF4052, Functions expanding.

Pin63: This pin is connected to the HEF4052, Functions expanding.

Pin64: IR signal input.

2 Memory AT24C08 is an E2PROM of 8k, pins describe as follows:

Pin1, Pin2, Pin3,Pin4, Pin7: GND. Pin8: +5V supply.

Pin5: SDA. Pin6: SCL.

3 HEF4052 is described as follows:total 16 pins

HEF4052 Pin9 HEF4052 Pin10 STATE

0 0 TV

0 1 AV

Pin8: GND.

Pin16: +5V supply.

4

4. Signal process

T

he main chip is N301 TDA93X1 AV control switch HEF4052, sound driver is N101

A

N17821A。

T

he TV signal inputs into the tuner (A101) from CABLE or antenna. The pin 10 and pin 11 of the

N301 are combined to select the band. The pin 4 of the N301 outputs the PWM tuning signal. The IF

video signal comes from the IF pin of the tuner. The 38.9MHz IF signal is coupled to the V308

(pre-amplify) and then to SAWF (Z301). After processed in the SAWF, the 38.9MHz signal gets to the

pin 23 and pin 24 of TDA93X1. The IF circuit in TDA93X1 includes such unit as the AGC amplifying

circuit, 38.9MHz oscillator, PLL video demodulator, video amplifier, IF identify circuit and AFT

circuit. The demodulated signal (CVBS) comes from the pin 38 of TDA93X1, the sound signal comes

from the pin 44.The internal CVBS signal needs norm identification then outputs from the pin 38 of

TDA93X1, via the trap-wave circuit (composed of the V351, Z354, Z352) feeds back to the pin 40 of

TDA93X1. The RGB signal comes from the pin51, Pin52, Pin53 of TDA93X1, and outputs to the

CRT board.

T

he internal sound signal comes from the pin 44 of TDA93X1, via the coupling capacitor C367

connects to the pin 3 and 5 of TDA9859. The TDA9859 is the audio effect processor, the AN7522N

is the driver. The TDA9859 includes bass, treble, balance, surround, effect shortcut options.

Through Synchronous separating circuit, the video signal is divided into

orizontal-Synchronizing signal and Vertical-Synchronizing signal. The horizontal-Sync pulse coming

from the pin 33 is ransferred to the horizontal-drive transistor, and will be used to drive the

horizontal-transformer. The horizontal-switch transistor is V451, it and the +B supply drives the

flyback transformer to generate the anode high voltage, the focus voltage, the screen voltage, the

CRT board drive voltage 180V, the vertical drive voltage 15V and -15V.

The vertical sawtooth wave is generated on the pin 21 and 22, and then enters the vertical output

amplifier circuit. The vertical output amplifier circuit is realized with the power amplifier IC

–LA78040.

T

he TDA8177 is a 7 pins vertical deflection circuit (2 Amperes) for DC-coupled 90° or 110°

deflection systems with frame frequencies from 50 up to 120 Hz. Only a single supply voltage for the

scan and a second supply for the flyback are needed.

T

he vertical drive currents of N301 pins 21 and 22 are connected to input pins 1 and 7 of the

TDA8177. The currents are converted into a voltage by resistor R405. Pin 2 is on a fixed DC level

(internal bias voltage, about 2.3V) and on pin 1 the drive voltage can be measured (typical 1.4 Vpp).

5

The outputs (pins 4 and 7) are connected to the series connection of the vertical deflection coil and

feedback resistor R404 and R406. The voltage across R404 and R406. is fed via pin 1 to obtain a

deflection current which is proportional to the drive voltage. The supply voltage for the TDA8177 is

17V at pin 3. The flyback generator has a separate supply voltage of V on pin 6. On pin 4 a vertical

guard signal is available. For HF loop stability a damping resistor R407 is connected across the

deflection coil.

6

. Power supply

T

he IC of KA5Q0765RT is adapted in this chassis; it is the product of Fairchild. It supplies four

DC voltages, one is the +B＝110V, another is Hcc＝26V, the third is 13V (the sound drive voltage),

the fourth is +16V. The +16V can generate the +8V, +5V and +3.3V by the special generators.

5 . IC illustration
Fig.1 TDA93X1 illustration

6

7

Fig.2 HEF4052BP illustration

Fig. 3 TDA8177 illustration

-

AMP

+

Thermal

Protection

1 INVERTING INPUT 5 VER OUTPUT
2 Vcc 6 OUTPUT STAGE VCC

Pump up

.

3 PUMP UP OUT 7 NON INV.PUT
4 GND

8

Fig. 4 AN17821A illustration

9

Fig. 5 KA5Q0765RT illustration

10 11

Fig. 6 TDA9859 illustration

12

6 . adjustment method

Main power +B setting

Receive standard color pattern RF signal，set picture to “ Standard Mode” . Adjust VR501，

to get +B (VD631 -) voltage =110 V

I2C bus control adjustment methed:

7 .

enter and exit factory mode

7.1

1) For remote controller of factory

continuous push [test] key on remote controller, the TV mode will change as follow:

Normal M BUS OPEN you can select “M” ( factory mode ) or “normal” mode.

2)

For remote controller of user

Push [menu] key, → display picture manual → push digital key 8500 → display M.

Push [standby] key , exit factory mode and TV will be standby.

7.2 MENU8 Geometrical adjustment .

Receive standard Crosshatch pattern signal for PAL system .

1) Adjust VSLOPE value，to the horizontal line just appear from

half bottom shadow.

2) Adjust VSHIFT value，the center horizontal line correspond to

CRT vertical center.

3) Adjust Vamp value，to get 90% of vertical picture contents would be displayed on CRT.

4) Adjust HSHIFT value，to get the picture horizontal center correspond to CRT horizontal center.

5) Receive standard Crosshatch pattern signal for NTSC system, and again adjust.

7.3 MENU7 AGC-TOP adjustment

Receive 60dBu (1mv)VH color bar signal，adjust AGC value（voltage from high to low），to

picture noise reduce gradually to be just disappeared.

7.4 MENU9 CRT cut-off and white balance and sub-brightness adjustment.

Reseive gray and white 2 steps signal.

a) CRT cut off adjustment.

Horizontal line

Shadow

1. push [▲P+][▼P-] key to select “SC”, push [►V+][◄V-] key then automatically vertical 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).

3. push [V+][V-] key again, vertical scan work repeat.

b) white balance adjustment.

13 14

1. select RD/BD menu.

2. adjustment RD/BD to get color temperature as x=281, y=311.

c) sub-brightness adjustment (use stair case signal)

1. select SB MENU.

2. adjust SB to get the darkest step being on or off.

7.5 MENU6 Set SHIP MODE

Select “SHIPMODE”，push [V+][V-]key may be shipped.

Note::

M

ay increase the screen of FBT current, the darking single ought no flyback line, AV state.

7.6 I2C bus control adjustment item default setting (21 inch)

NT

DA93X1

MI items variable preset remark

M0 AVL ON/OFF ON

The factory menu constitution

Automatic volume the electricity is even to limit to

choose the switch

FSL ON/OFF OFF

FMWS ON/OFF ON

FFI ON/OFF OFF

OSO ON/OFF ON

FCO ON/OFF OFF

WOOFER ON/OFF OFF

The Forced slicing( the limit) level for vertical syn.

Window selection of narrow-band sound PLL.

Fast filter if-PLL.

Switch-off in vertical overscan.

Compulsory colorful switch of weak signal.

Have the heavy bass function choice switch of hour

of TDA9860.

DUAL OUT 0~1 1

Have the TDA9874 a track companion sound of hour

to output.

Volume mode 0~1 1

VOL PIN OPEN- DRAIN/

PUSH- PULL

M1 BAND 0~2 1

AV CFG 0~9 9

NTSC MX USA

VIDEO OUT CVBS

PUSH-PULL

One choice of the companion sound curve.

The volume control feet output the way choice.

The tuner wave band control choice.

The video frequency function install.

The NTSC decoding matrix choice.

Have already chosen the video frequency exportation

choice.

IF: picture in the IF CVBS: output with the screen

PIN5 RGB

PRO 0~3 0

M2 VISION IF 38.9M

The UOC pin5 function choice.

The picture prepares the blunt adjustment.

IF chooses in the picture.

DK ON/OFF ON

Companion sound DK make type choice.

BG ON/OFF ON

I ON/OFF ON

M ON/OFF OFF

SIF PREFER BG

AUTO SOUND ON/OFF ON

M3 START ON 0-3 1

The automatic companion sound make type identify

Switch on the power supply appearance choice, know

Companion sound BG make type choice.

Companion sound I make type choice.

Companion sound M make type choice.

Companion sound make type prior choice.

well to see Note3.

ENGLISH ON/OFF ON

ARABIC ON/OFF ON

PERSIAN ON/OFF ON

TURKISH ON/OFF ON

FRANCE ON/OFF ON

RUSSIA ON/OFF ON

Spanish bit 0~1 0

English holds to show the language choice.

ARABIC holds to show the language choice.

PERSIAN holds to show the language choice.

TURKISH holds to show the language choice.

FRANCE

RUSSIA holds to show the language choice.

holds to show the language choice.

In the diagram text the Spanish character list

manifestation switch.

TXT DEF 0~3 0

TXT BRI 0-32

TXT LIST 0~1 0

M4 SUBCON 0~63 36

SUBCOL 0~63 63

SUBSHP 0~63 25

SUBTINT 0~63 32

YDLY PAL 14

YDLY NTSC 5

YDLY SEC 14

YDLY AV 15

UOC VOL OFF

UOC VOL 0~63 50

CATHODE 0~15 4

8

The diagram text district constitution switch, know

well to see Note1.

A constitution of hour of the diagram text appearance.

The diagram text fast index function constitution

switch.Know well to see the annotation 2 Note2.

Sub contrast.

Sub colour.

Pay the clear degree regulate.

Pay the tone regulate.

Regulate when bright degree of PAL postpone.

Regulate when bright degree of NTSC postpone.

Regulate when bright degree of SECAM postpone.

Regulate when bright degree of AV postpone.

The volume switch choice inside the UOC.

The volume switch inside the UOC regulate.

The cathode electricity is even to regulate.

TDA9874 GAIN 0~32 15

SC BRI 0~63 32

M5 OSD VPOS 0~63 46

OSD HPOS 0~59 17

15

The TDA9874 outputs to increase the benefit to

regulate.

The bright degree of bright line hour of level

regulate.

OSD hight position adjustment.

OSD horizontal position adjustment.

WIDE 0~63 8

16:9 breadths hold a range regulate.

ZOOM 0~63 34

NENU TITLE 0~6 3

M6 LOGO ON

LOGO SIZE 1

BIG LOGO START 0

LOGO COLOUR 0

LOGO PSITION 0

LOGO CHAR

SEARCH SPEED 0

SHIPMODE

M7 AGC-TOP 0~63 36

AGC-TIME 0~3 1

SP1 0~63 15

SP16 0~63 52

Enlarge a range of appearance regulate.

Hold to show a color of the menu headline to regulate.

Switch on the LOGO size choice switch..

Greatly switch on constitution switch of LOGO.

Greatly switch on constitution switch of LOGO.

Switch on the LOGO color constitution.

Switch on character list position of LOGO.

Switch on the LOGO character list choice.

Search the speed choice switch.

A constitution with automatic factory.

The AGC rises to control to order to regulate.

The AGC constant choice.

2 spots of the companion sound curve 1, the

recommendation be worth 20.

2 spots of the companion sound curve 16, the

recommendation be worth 35.

SP32 0~63 56

2 spots of the companion sound curve 32, the

recommendation be worth 45.

SP48 0~63 58

2 spots of the companion sound curve 48, the

recommendation be worth 60.

START TIME 0~15 6

M8 VSLOPE 50HZ 34 60HZ 34

VSHIFT 34 34

VAMP 25 25

VSCOR 26 26

HSHIFT 32 32

RGB HS 32 32

Switch on time constitution.

hight line position regulate.

hight position regulate.

Hight range regulate.

VS correction.

Horizontal position.

YUV or the RGB appearance hour, go the position to

regulate.

M9 BT 40

CT 34

SC OFF

Adjust bright degree of the white balance.

Adjust the white and equilibrium contrast degree.

Adjust the bright line.

RB 32

GB 32

RD 32

16

Green close to give or get an electric shock the even

Red close to give or get an electric shock the even

adjustment.

adjustment.

Red encourage to give or get an electric shock the

even adjustment.

GD 32

Green encourage to give or get an electric shock the

even adjustment.

BD 32

Blue encourage to give or get an electric shock the

even adjustment.

SB 40

The vice- bright degree adjust.

Note1:

TEXT DEF : TXT_def = 0: Pan_Euro + Cyrillic

= 1: Farsi English + French + Turkish

= 2: Arabic + English + French + Turkish

= 3: UKRAINIAN

Attention:

When TXT_def=0, will appear" the TXT LANGUAGE" in the customer Setup menu,

press V+/ V- key," the TXT LANGUAGE" will appear the following circulation: W- TR-> EAST1->

EAST2-> W- TR

The W- TR diagram text includes the following language:

English German Swedish/Fin/Dan/Hungarian Italian French Spanish/Portuguese Turkish

The EAST1 diagram text includes the following language:

Polish German Estonian Slovenian Czech/Slovak Rumanian

The EAST2 diagram text includes the following language:

Polish German Swedish/Fin/Dan/Hungarian Lettish Russian Slovenian Czech/Slovak Estonian

Note 2:
Make use of 4 color keys of the remote control, browse 4 pages of the enactment
quickly, namely index function.
The TV/ AV sets the saving key for the index.
While using this function," the TXT LIST" establishes for" ON" in the customer menu.

Example: if want to use the color key of the red quickly 230 pageses of enter the
diagram text
The sequence press" TEXT"," red key","2","3","0" on the remote control," TV/ AV"

Note 3:
Switch on the hour appearance constitution
0: connect the AC power, enter to need the machine appearance automatically
1: connect the AC power, automatically switch on appearance
2: connect the AC power, if shut down the appearance as the diagram text
appearance, enter the diagram text appearance automatically

17