Akira | 21WHS3 | Colour TV Service Manual

Colour TV
Service Manual
2
Model: 21WHS3/BN
Chassis: UOC-TDA9381
Model No: 21WHS3BN
Version 1.0
3
CONTENT
SPECIFICATION .................................................................................................................................... 4
THE SURVEY ......................................................................................................................................... 5
THE MAIN CHIPS INSTRUCTION....................................................................................................... 6
SIGNAL PROCESS ................................................................................................................................. 8
THE HORIZONTAL AND VERTICAL CIRCUIT ................................................................................ 9
FACTORY MENU................................................................................................................................. 11
APPENDIX ............................................................................................................................................ 14
CIRCUIT DIAGRAM ............................................................................................................................ 18
EXPLODED VIEW WITH PART NAME ............................................................................................ 19
Model No: 21WHS3BN
Version 1.0
4
SPECIFICATION
Rated Voltage
Power Consumption
Sound output:
Screen size
System:
Color
Sound
Channel coverage:
IF
External input/output
I2C Bus Control
Auto Search
Off/On Timer
Teletext
Model No: 21WHS3BN
Version 1.0
AC 110V~250V 50Hz/60Hz
65W
3W×2
Picture tube 21 inch
RF
PAL SECAM
AV
NTSC
D.K / B.G
VHF Low channel (VL)
=48.25 to 147.25 MHz
VHF high channel (VH)
=154.25 to 463.25 MHz
UHF channel (U)
=471.25 to 863.25 MHz
38MHz
Video/Audio (L/R) 1set input at side
YUV & SVHS at rear
AV output at rear
5
THE SURVEY
Table 1, the main IC and functions
Number
Function
IC
Remark
1
Power supply
KA5Q0765RT
N501
2
CPU + SIGNAL PROCESSER
TDA9381
N301
3
Field driver
LA78040 STV9302A
N401
4
Sound processor
TDA9859
N122
5
Sound driver
AN7522N(stereo)
N161
6
AV SWITCH
TC4052BP
N801 (Video)
7
5V Regulator
L7805CV
N505
8
8V Regulator
L7808CV
N503
9
Memory
AT24C08
N702
10
Photo-coupler
HS817B
N504
11
IR-receiver
HS0038A
U701
Model No: 21WHS3BN
Version 1.0
6
THE MAIN CHIPS INSTRUCTION
The UOC (“Ultimate One Chip”) TDA9381/61 is adopted in this chassis. This IC is the first available
component that contains the complete control and small signal functionality needed for a TV
application in one device.
1.
The UOC TDA9361/81 pins function description: ( total 64 pins)
Pin1:
Pin2:
Pin3:
Pin4:
Pin5:
Pin6:
Pin7:
Pin8:
Pin9, Pin12,Pin18,
Pin30, Pin35, Pin41,
Pin55:
Pin10 & Pin11:
Pin13:
Pin14:
Pin15:
Pin16:
Pin17:
Pin18:
Pin19:
Pin20:
Pin21, Pin22:
Pin23, Pin24:
Pin25:
Pin26:
Pin27:
Pin28:
Pin29:
Model No: 21WHS3BN
Version 1.0
Standby control,“1” is on,“0”is off.
SCL.
SDA.
Tuning PWM output.
NTSC SWITCH.
Key board input.
VOL1, controls the 9 pin of the N101 and supplies DC voltage.
Mute control,“1” is mute,“0”is off.
GND.
Band control of the tuner, the two pins needs the pull-up resistance.
SECAM PLL, connected with a capacitor.
+8V power source supply.
Using a capacitor of 220n in series to GND, This pin decouples the internal
digital supply voltage of the video processor and minimizes the disturbance to
the sensitive analogue parts.
PHI-2 control loop, this pin requires a capacitor at 2.2nF (C) in series to GND.
PHI-1 control loop, the loop filter connected to pin 17 is suitable for various
signal conditions like strong/weak and VCR signal. This is achieved by
switching of the loop filter time constant by changing the PHI-1 output
current.
GND
Bandgap decoupling, the bandgap circuit provides a very stable and
temperature independent reference voltage. This reference voltage (4.0 V)
ensures optimal performance of the analogue video processor part of the
TDA9381 and is used in almost all functional circuit blocks.
AVL filter, according to the different soft edition.
Vertical drive output.
IF input.
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 because the geometry processor is
optimized for this current. Furthermore the output current of vertical drive and
EW are proportional to this current.
Vertical saw tooth, This pin requires a capacitor to ground of 100nF.
AGC output. This output is used to control (reduce) the tuner gain for strong
RF signals.
Audio de-emphasis.
Sound decoupling. This pin requires a capacitor connected to ground. The pin
acts as a low pass filter needed for the DC feedback loop.
7
Pin30:
Pin31:
Pin32:
Pin33:
Pin34:
Pin35:
Pin36:
Pin37:
Pin38:
Pin39:
Pin40:
Pin42:
Pin43:
Pin44:
Pin45:
Pin46, Pin47,
Pin48:
Pin49:
Pin50:
Pin51, Pin52,
Pin53:
Pin54:
Pin55:
Pin56:
Pin57, Pin58,
Pin59:
Pin60:
Pin61:
Pin62 & Pin63:
Pin64:
2.
GND.
Sound loop filter.
AVL filter, according to the different soft edition.
Horizontal drive signal output, needs a resistance in series to +8V.
Sandcastle output/flyback input.
External audio input, this pin is no use.
EHT tracking/ over voltage protection. If something is wrong, the anode high
voltage rises, the heater voltage will rise too. When the rising voltage arrive
some limit, the V406 works, the voltage of pin 36 will exceed 3.9V, the
TDA9381 will stop working.
PLL loop filter.
CVBS output. Monitor or RF videos can be selected.
+8V supply source.
CVBS input
Y signal input.
C signal input.
Main audio output, this pin is connected to the TDA9859.
YUV signal input control voltage, 0 = Pin 45 low (< 0.4V), no insertion,
1 = Pin 45 above insertion level (>0.9V), YUVIN inserted.
YUV signal input.
ABL. It means beam current limiter input. The R462 & R463 are the control
resistances.
Black current input from the CRT board.
RGB drive signal output to the CRT board.
+3.3V.
GND.
+3.3V.
12MHz crystal.
Reset, NC in this chassis.
+3.3V
The AV control pins.
IR signal input.
Memory AT24C08 is an E2PROM of 8k, pins describe as follows:
Pin1, Pin2, Pin3,
Pin4, Pin7:
Pin8:
Pin5:
Pin6:
Model No: 21WHS3BN
Version 1.0
GND.
+5V-1 supply.
SDA.
SCL.
8
SIGNAL PROCESS
The main chip is N301 TDA9381, AV control switch HEF4052 (video), sound process chip is
TDA9859 (AV audio), sound driver is N601 AN7522N.
The TV signal inputs into the tuner (A201) 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 38MHz IF signal is coupled to the V308 (preamplify) and then to SAWF (Z301). After processed in the SAWF, the 38MHz signal gets to the pin 23
and pin 24 of TDA9381. The IF circuit in TDA9381 includes such unit as the AGC amplifying circuit,
38MHz oscillator, PLL video demodulator, video amplifier, IF identify circuit and AFT circuit. The
demodulated signal (CVBS) comes from the pin 38 of TDA9381, the sound signal comes from the pin
44.
The internal CVBS signal needs norm identification then outputs from the pin 38 of TDA9381, via the
trap-wave circuit (composed of the V351, Z351, Z352 and so on) feeds back to the pin 40 of TDA9381.
The RGB signal comes from the pin51, Pin52, Pin53 of TDA9381, and outputs to the CRT board.
The V911, V921 and V931 are the R、 G、 B drive transistors. The V912, V913, V922, V923, V932,
V933 are the auto low bright balance level output circuit, and generate the low bright level current into
the pin 50 of TDA9381.
The internal sound signal comes from the pin 44 of TDA9381, 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, additional
the audio input switch.
Model No: 21WHS3BN
Version 1.0
9
THE HORIZONTAL AND VERTICAL CIRCUIT
Through Synchronous separating circuit, the video signal is divided into horizontal-Synchronizing
signal and Vertical-Synchronizing signal. The horizontal-Sync pulse coming from the pin 33 is
transferred 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 190V, 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 or STV9302A.
The STV9302A is a 7 pins vertical deflection circuit (3 Amperes) for DC-coupled 90° deflection
systems with frame frequencies of 50 or 60 Hz. Two single supply voltages for the scan and two
supplies for the flyback are needed.
The vertical drive currents of TDA9381 pins 21 and 22 are connected to input pins 1 and 7 of the
STV9302A. Pin 2 is the +15V DC power supply voltage, Pin 4 is the -15V DC power supply voltage.
The outputs (pin5) is connected to the series connection of the vertical deflection coil and feedback
resistor R406. The voltage across R406 is fed via pin 1 to obtain a deflection current which is
proportional to the drive voltage.
Model No: 21WHS3BN
Version 1.0
10
Power supply
The 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. The fifth is +12V, it generate the +5V and +3.3V by
the special generators.
Fig.1 The power supplies illustration
L501
L503
VD503
VD504
VD505
VD506
AC 22V
C507
N501
T501
N504
DC
+26V To V450, T450
VD52
VD522
+13V To N101
+12V To N505 +5V
VD543 +12
V542 N503
VD524
+190V To CRT
VD47
R561
VD564
+15V To Pin 2 of N401 VD47
-15V To Pin 4 of N401
VD470
+3.3V To
HEARTER VOLTAGE
R480
+8V
Pin 1 of N301 is high level
Model No: 21WHS3BN
Version 1.0
V504 is ON
11
FACTORY MENU
Factory menu
M0
AVL
Items
Variable
ON/OFF
Preset data
ON
Remark
Unadjustable
M0
M0
M0
M0
M0
M0
M0
M0
M0
FSL
FMWS
FFI
OSO
FCO
WOOFER
DUAL OUT
Volume mode
Vol pin
ON/OFF
ON/OFF
ON/OFF
ON/OFF
ON/OFF
ON/OFF
0~1
0~1
Push-pull open-drain
OFF
ON
OFF
ON
OFF
OFF
0
1
Push-pull
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
M1
M1
M1
M1
M1
M1
BAND
AV CFG
NTSC MX
VIDEO OUT
PIN5
PRO
0~2
0~9
USA JAP
IF CVBS
NTSC RGB
0~3
2
3
USA
CVBS
RGB
0
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
M2
M2
M2
M2
M2
M2
M2
VISION IF
DK
BG
I
M
SIF PREFER
AUTO SOUND
38 38.9M
ON/OFF
ON/OFF
ON/OFF
ON/OFF
BG DK I M
ON/OFF
38M
ON
ON
OFF
OFF
DK
ON
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
M3
M3
M3
M3
M3
M3
M3
START
ENGLISH
ARABIC
PERSIAN
TURKISH
FRANCE
RUSSIA
ON/OFF
ON/OFF
ON/OFF
ON/OFF
ON/OFF
ON/OFF
ON/OFF
ON
ON
ON
ON
ON
ON
ON
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
Model No: 21WHS3BN
Version 1.0
12
Factory menu
M4
Items
SUBCON
Variable
0~63
Preset data
45
Remark
Adjustable
M4
M4
M4
M4
M4
M4
M4
M4
M4
M4
SUBCOL
SUBSHP
SUBTINT
YDLY PAL
YDLY NTSC
YDLY SEC
YDLY AV
UOC VOL
UOC VOL
CATHODE
0~63
0~63
0~63
0~15
0~15
0~15
0~15
ON/OFF
0~63
0~15
63
36
28
7
7
7
7
OFF
45
7
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
M5
M5
M5
M5
M5
M5
M5
M5
OSD VPOS
OSD HPOS
WIDE
ZOOM
NENU TITLE
LOGO ADDRESS
LOGO VALUE
LOGO WRITE
0~63
0~48
0~63
0~63
0~6
0~33
0~95
***
53
9
2
53
3
0
0
***
Adjustable
Adjustable
Adjustable
Adjustable
Unadjustable
Unadjustable
Unadjustable
Unadjustable
M6
M6
SHIPMODE
SEARCH SPEED
0~3
0
Unadjustable
Adjustable
M7
M7
AGC-TOP
AGC-SPEED
0~63
0~3
28
2
Adjustable
Unadjustable
Model No: 21WHS3BN
Version 1.0
13
Factory menu
M8
Items
FREQUENCY
M8
M8
M8
M8
M8
M8
M8
VSLOPE
VSHIFT
VAMP
VSCOR
HSHIFT
RGB HSHIFT
RGB POS
M9
M9
M9
M9
M9
M9
M9
M9
M9
BT
CT
SC
RB
GB
RD
GD
BD
SB
Variable
50 60HZ
Preset data
50HZ
Remark
Adjustable
0~63
0~63
0~63
0~63
0~63
0~63
0~48
30
36
28
31
31
31
31
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
0~63
0~63
ON/OFF
0~63
0~63
0~63
0~63
0~63
0~63
45
48
OFF
32
32
32
32
32
40
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Unadjustable
M entrance process:
First press the menu, when the picture (bright and contrast) OSD reveals, then
press 8500.
Model No: 21WHS3BN
Version 1.0
14
APPENDIX
HEF4052B illustration
Model No: 21WHS3BN
Version 1.0
15
TDA9859 illustration 1
Model No: 21WHS3BN
Version 1.0
16
TDA9859 illustration 2
Model No: 21WHS3BN
Version 1.0
17
KA5Q0765RT illustration
AN7522N illustration
Model No: 21WHS3BN
Version 1.0
19
EXPLODED VIEW WITH PART NAME
Model No: 21WHS3BN
Version 1.0
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