Belson bsv29251 schematic

C.E.C BELSON/DPTO.TECNICO/MOD:BSV-29251/Ed.01

BelsonBelson

SERVICE SERVICE

MANUALMANUAL

BSV-29251

CONTENTS

SAFETY INSTRUCTION AND PRODUCT SAFETY NOTICE………………………..……1 X-RAY RADIATION PRECAUTION………………………………………………………1

SAFETY PRECAUTION…………………………………………………………………..1 PRODUCT SAFETY NOTICE…………………………………………………………….2 ALIGNMENT PROCEDURE…………………………………………………………….3 TEST EQUIPMENT……………………………………………………………………3 ALIGNMENT INSTRUCTION………………………………………………………………..3 B+ CONFIRM……………………………………………………………………………………3 AGC ALIGNMENT………………………………………………………………………………4 SOUND CHECK…………………………………………………………………………………4 FOCUS POTENTIOMETER ADJUSTMENT…………………………………………………4 H-CENTER ADJUSTMENT……………………………………………………………………4

V-SIZE, VERTICAL S-CORRECTION, V-CENTER, H-SIZE, E/W CORRECTION

ADJUSTMENT……………………………………………………………………………4 SCREEN-GRID VOLTAGE VG2 ADJUSTMENT…………………………………………4 WHITE BALANCE ADJUSTMENT(AUTO DARK BALANCE)……………………………4 LUMINANCE/CHROMA TIME DELAY ADJUSTMENT……………………………………5 HIGH VOLTAGE AND FILAMENT VOLTAGE CHECK……………………………………5 X-RAY PROTECTION CHECK………………………………………………………………5 BEAM CURRENT CHECK……………………………………………………………………5 AV F U N C T I O N C H E C K ………………………………………………………………………5 OUT-FACTORY STATUS SETTING…………………………………………………………5 APPENDIX 1……………………………………………………………………………………6 APPENDIX 2……………………………………………………………………………………8 WIRING DIAGRAM……………………………………………………………………….9 BLOCK DIAGRAM………………………………………………………………………...10 IC BLOCK DIAGRAM……………………………………………………………………..11 SCHEMATIC DIAGRAM………………………………………………………………….15 ELECTRICAL PARTS LIST………………………………………………………………16

CAUTION: THIS SERVICE MANUAL IS ONLY FOR PROFESSIONAL SERVICE PERSONNEL’S

REFERENCE. BEFORE SERVICING THIS CHASSIS, PLEASE READ THE

FOLLOWING NOTICE ITEMS.

1. SAFETY INSTRUCTION AND PRODUCT SAFETY NOTICE

Before servicing and aligning this equipment, please read the following “X-RAY RADIATION PRECAUTION” ,“SAFETY PRECAUTION” and “PRODUCT SAFETY NOTICE”.

1.1 X-RAY RADIATION PRECAUTION

Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To avoid such hazards,

the high voltage must not be above the specified limit. The normal value of the high voltage of this

receiver is: 26.5kV(25”) at 1.3mA beam current; 29kV(29” super flat) at 1.4mA beam current; 30kV(29”

pure flat) at 1.4mA beam current. The high voltage must not, under any circumstances, exceed

31kV(25”)/33kV(29”)/35kV(29” pure flat).

Each time a receiver requires servicing, the high voltage should be checked following the HIGH

VOLTAGE CHECK procedure in this manual. It is recommended the reading of the high voltage be

recorded as a part of service record. It is important to use an accurate and reliable high voltage meter.

The primary source of X-RAY RADIATION in this TV receiver is the picture tube. For continuous X-RAY

RADIATION protection, the replacement tube must be exactly the same type tube as specified in the parts

list.

Some parts in this receiver have special safety-related characteristics for X-RAY RADIATION protection.

For continuous safety, parts replacement should be undertaken only after referring to the PRODUCT

SAFETY NOTICE below.

1.2 SAFETY PRECAUTION WARNING:

Service should not be attempted by anyone unfamiliar with the necessary precaution on this receiver. The

following are the necessary precautions to be observed before servicing this chassis.

1) Since the power supply circuit of this receiver is directly connected to the AC power line, an isolation

transformer should be used during any dynamic service to avoid possible shock hazard.

2) Always discharge the picture tube anode to the CRT conductive coating before handling the picture tube.

The picture tube is highly evacuated and if broken, glass fragments will be violently expelled. Use shatter

proof goggles and keep picture tube away from the unprotected body while handling.

3) When replacing a chassis in the cabinet, always be certain that all the protective devices are put back in

place, such as: non-metallic control knobs, insulating covers, shields, isolation resistor-capacitor network

etc.

4) When replacing parts or circuit boards, disconnect the power cord.

5) When replacing a high wattage resistor (oxiode metal film resistor) on the circuit board, keep the resistor

10mm (1/2in) away from circuit board.

6) Connection wires must be kept away from components with high voltage or high temperature.

7) If any fuse in this TV receiver is blown, replace it with the FUSE specified in the chassis parts list.

8) Before returning the set to your customer, always perform an AC leakage current check on the exposed

metallic parts of the cabinet, such as antennas, terminals, screwheads, metal overlays, control shafts etc. to

be sure the set is safe to operate without danger of electrical shock. Plug the AC power cord into a 220V

AC outlet (do not use a line isolation transformer during this check). Use an AC voltmeter having 5000

ohms per volt or more sensitivity in the following manner:

Connect a 1500 ohm 10 watt resistor, paralleled by a 0.15µF, AC type capacitor, between a known good

earth ground (water pipe, conduit, etc.) and the exposed metallic parts, one at a time. Measure the AC

voltage across the combination of 1500 ohm resistor and 0.15µF capacitor. Reverse the AC plug at the AC

outlet and repeat AC voltage measurements for each exposed metallic part. Voltage measured must not

exceed 0.3 volts RMS. This corresponds to 0.2 milliamp. AC. Any value exceeding this limit constitutes a

potential shock hazard and must be corrected immediately.

AC VOLTMETER

9) DC voltage breakdown test

Good earth ground such as a water pipe, conduit, etc.

C. R.

Place this probe on Each exposed Metallic part.

Before packing, the following touchable parts should be conducted with withstand voltage test for 1s.

Apply the voltage and test, the voltage should be AC 3000V.

Part name : Position:

Antenna terminal Back cabinet

Outcabinet screws Back cabinet

AV terminals Back and side

1.3 PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in the chassis 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 wattage, etc. Replacement parts which have these special safety characteristics are identified in

this manual and its supplement electrical components having such features are shaded on the schematic

diagram and the parts list.

Before replacing any of these components, read the parts list in this manual carefully. The use of

substitute replacement parts which do not have the same characteristics as specified in the parts list may

create shock, fire, X-RAY RADIATION or other hazards.

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C.E.C BELSON/DPTO.TECNICO/MOD:BSV-29251/Ed.01

2 Alignment procedure

The alignment procedure flow chart see below figure:

EEPROM copy

Chassis

B+ check

V-size V-linearit

rough adjust

H-size, E/W pincushio correction roug adjust

RF AGC

Sound check

The whole unit

Focus rough adjust and aging

VG2 adjust

White balance and

sub-brightness adjust

H-center V-center and

V-size realign

H-size and E/W

correction

OSD vertical position

Focus fine-adjust

Check

Fig.2

High voltage

check

Filament voltage

check

X-ray protection

check

Picture and

sound check

White balance

check

or purity

convergence

check

Luminance, chroma time dela

AV terminal

check

The TV set

button’s function

check

The remote controller’s

function check

Installation and

packing check

Safety check

3. TEST EQUIPMENT

3.1 DC regulated power supply PAB18-1.8

3.2 Audio voltameter

3.3 Oscilloscope

3.4 High-voltage meter

3.5 Digital multimeter

3.6 AC break-down testing equipment 4 Alignment instruction

The way to enter into factory alignment menu by using remote control: when there is no OSD on the

screen, in turn press MIX, CANCEL, HOLD and REVEAL button and the period of two-press should be

less than 3 seconds. To exit, press TV button.

4.1 B+ confirm

Use DC voltameter of DC200V to check B+ voltage (C529 two terminals), 29” pure flat CRT should

be 140V or 138V (depending on different CRT), the error is

0.5 V.

4.2 AGC alignment

4.2.1 Receive D-8 signal 60 dB, use DC voltameter to measure C104 positive pole testing point voltage.

4.2.2 Adjust TOP item to make AGC voltage just start dropping from highest point (about 4V).

4.2.3 From antenna input inputs 100 dB signal, the picture should not appear non-synchronization and

distortion. Input 35 dB

40 dB weak signal, the colour should not appear and picture is in

synchronization and sound is normal.

4.3 Sound check

4.3.1 Receive 1kHz 100% modulation sound signal, XV03 connect with a simulated speaker load of 8 ohm,

audio voltmeter or oscilloscope measure the voltage of the load.

4.3.2 Turn the volume to maximum, the sound power consumption should be

the distortion should be

7% (allow maximum volume sine wave have clipping distortion)

7 W 2 (about 7.5 Vrms),

4.4 Focus potentiometer adjustment

4.4.1 The whole unit preheats 30 minutes.

4.4.2 Receive testing signal.

4.4.3 Press PP button to select DYNAMIC mode.

4.4.4 Adjust FBT’s FOCUS potentiometer to make picture clearest.

4.5 H-center adjustment

4.5.1 Receive 50 Hz testing signal.

4.5.2 Enter into 5HSH item, adjust the level to make picture symmetry in horizontal.

4.5.3 Receive 60Hz testing signal. To 6HSH adjust, the method is as same as the above two steps.

4.6 V-size, Vertical S-correction, V-center, H-size, E/W correction adjustment (50 Hz/60 Hz

independently)

4.6.1 Receive testing signal, enter into factory menu VSL item, adjust the value to make picture’s lower half

part just disappear.

4.6.2 Enter into factory menu corresponding item, adjust the value to make V-center and CRT’s geometrical

center be in accordance, vertical S-linearity be proper and vertical reproduction rate be

90%.

4.6.3 Enter into factory menu corresponding items, adjust horizontal geometrical distortion until be in proper.

EWW Adjust H-size

EWP Adjust east/west pincushion correction size

EWT Adjust east/west trapezoid size

UCT Adjust east/west left upper corner and right upper corner distortion

LCR Adjust east/west left lower corner and right lower corner distortion.

BOW Adjust east/west arch.

PAR Adjust parallelogram.

The adjustment results meet scan linearity geometrical distortion and over-scan (reproduction rate)

requirements.

4.7 Screen-grid voltage VG2 adjustment

Enter into factory menu, set VG2B to 29, press digit button “0”, enter into alignment status, turn FBT

accelerated pole potentiometer to end anticlockwise, then clockwise turn the potentiometer until the

indication “OUTSIDE LOW” just jump to “INSIDE HIGH”.

4.8 White balance adjustment (auto dark balance)

4.8.1 Dark balance just need fine tune, under 4.5 nit, colour temperature 12000K+8MPCD (X=0.270,

Y=0.283)

4.8.2 Bright balance also has already automatically adjusted at some white coordinate. Only need to fine tune

around 31 value, under 60 nits, colour temperature 12000K+8MPCD (X=0.270, Y=0.283)

4.9 Luminance/chroma time delay adjustment (YD_ _) Respectively input PAL,SECAM,NTSC RF signal or PAL AV signal and adjust YD_ _ to make

luminance tallied with chroma.

For those model with SVM function, on the condition that SVM is set to ON, input split field or

crosshatch signal, respectively adjust YD_ _ until SVM’s edge from black to white is in symmetry with

that from white to black, give attention to the data that make luminance tallied with chroma.

4.10 High voltage and filament voltage check

4.10.1 Connect high voltage meter between CRT high voltage cap and GND, use effective and precise

voltameter to measure filament voltage.

4.10.2 Receive D35 signal, set picture mode to “DYNAMIC”. Measure the high voltage and filament voltage

and the reading should be: for 29” super flat CRT, the high voltage is 29 kV

flat CRT, the high voltage is 30 kV

0.5 kV, filament voltage 6.3 0.3 Vrms.

0.5 kV, for 29” pure

4.11 X-ray protection check

4.11.1 Receive normal picture.

4.11.2 Press S301 switch, horizontal scan should stop vibration and turn off.

4.11.3 Turn off the power switch and wait about 30 seconds, turn on the set again, it should restore to

normal.

4.12 Beam current check

Receive D35 signal, set picture mode to “DYNAMIC”, measure R313 two terminals, for 29” super flat

it should be

1.6 V, for 29” pure flat it should be 1.7V.

4.13 AV function check

According to Instruction manual, connect the AV equipment to the AV terminals which need to be

check, the following is required:

VIDEO IN: 1 Vp-p 75

, AUDIO IN: -8 dBm 3 dBm 47 k .

4.14 Out-factory status setting

Contrast: 45 Comb filter: ON

Brightness: 28 Blue back: ON

Colour: 40 Black stretch: ON

Sharpness: 35 SVM: ON

Treble: 31 AVL: OFF

Bass: 31 Surround: OFF

Balance: 0

The following appendix is factory menu and data.

C.E.C BELSON/DPTO.TECNICO/MOD:BSV-29251/Ed.01

Appendix 1 factory menu and data

Page/

Button

Item Meaning Reference value Remark

5PAR Horizontal parabola 0-63

5BOW Horizontal bow 0-63

5HSH Horizontal shift 0-63

5EWW EW width 0-63

5EWP EW parabola 0-63

5UCR EW upper corner parabola 0-63

5LCR EW lower corner parabola 0-63

5EWT EW trapezium 0-63

5VSL Vertical slope 0-63

5VAM Vertical amplitude 0-63

5SCL S-Correction 0-63

5VSH Vertical Shift 0-63

5VOF Text Position Vertical offset

6PAR Horizontal parabola 0-63

6BOW Horizontal bow 0-63

6HSH Horizontal shift 0-63

6EWW EW width 0-63

For 50Hz

6EWP EW parabola 0-63

6UCR EW upper corner parabola 0-63

6LCR EW lower corner parabola 0-63

6EWT EW trapezium 0-63

6VSL Vertical slope 0-63

RED WPR White Point R 0-63

GREEN WPG White Point G 0-63

6VAM Vertical amplitude 0-63

6SCL S-Correction 0-63

6VSH Vertical Shift 0-63

6VOF Text Position Vertical offset

VX Vertical Zoom

RED Black level offset R 32

GRN Black level offset G 32

28 25

BLUE WPB White Point B 0-63

YDFP Y-Delay for PAL

YDFN Y-Delay for NTSC

YDFS Y-Delay for SECAM

YDAV Y-Delay for AV

4 TOP AGC Take-Over Point 0-63

0-15

For 60Hz

Adjust around 31

Brightness, colour in

accordance. For model

with SVM function,

SVM edge should be

in symmetrical.

C.E.C BELSON/DPTO.TECNICO/MOD:BSV-29251/Ed.01

VOL Volume

9874 Gain control for TDA9874

IFFS Vision IF

HDOL Cathode drive level

AGC IF AGC speed

AG2B VG2 Brightness 33 Before adjust AG2, fix it

OP1 Option byte 1 218 (11011010)

OP2 Option byte 2 33 (00100001)

6 INT Initial E2PROM According to actual need initial EEPROM

7 LOGO Logo According to actual need set the logo.

8 STS Status

9 AGIN Aging(escape by local Menu) Press Menu button on the set to exit.

0 VG2 Adjust VG2

Note1: the letter in bold and italic is fixed setting.

Note2: use blank EEPROM, after turning on the set for the first time, please first initial EEPROM (at INT item

press VOL+ button), and reset other factory menu item.

OP3 Option byte 3 123 (01111011)

OP4 Option byte 4 251 (11111011)

OP5 Option byte 5 63 (00111111)

45 20 2 8 1

‘In High’/’Out Low’

or line disappear

2-38.9M,3-38M

+ 18 hidden pages

Belson bsv29251 schematic

Specifications and Main Features

Frequently Asked Questions

User Manual