TCL SY33 Schematic

TCL

SERVICE MANUAL

CRT CHASSIS SY33

1、 Caution………………………………………………………………………2
2、 Specification…………………………………………………………………6

3、 Alignment Procedure……… ……………………………………………… 8

4、 Block Diagram…………… …………………………………………… … 13

5、 Circuit Theory Introduction…………………… …………………………14

6、 Troubleshooting ……… ………… …………… ………… ……………16
7、 Schematic Diagram ……………………… ………………………………18

8、 Main IC Introduction………… …… ……………………………………20

9、 BOM list…………………… ………………………………………………30

This manual is the latest at the time of printing, and does not
include the modification which may be made after the printing, by
the constant improvement of product

CAUTION:

1、

Use of controls, adjustments or procedures other than those specified herein may result in
hazardous radiation exposure.

CAUTION: T O REDUCE THE RISK OF

CAUTION

RISK RISK OF OF ELECTRIELECTRICC

SHOCK SHOCK DO DO NOT NOT OPEN.OPEN.

The lighting flash with arrowhead symbol, with an equilateral triangle is intended to
alert the user to the presence of uninsulated voltage within the products
enclosure that may be of sufficient magnitude to constitute a risk of electric shock to
the person.

The exclamation point within an equilateral triangle is intended to alert the user to the
presence of important operating and maintenance (servicing) instructions in the
literature accompanying the appliance.

ELECTRICAL SHOCK, DO NOT REMOVE
COVER (OR BACK). NO USER SERVICEABLE
PARTS INSIDE. REFER SERVICING TO
QUALIFIED SERVICE PERSONNEL.

dangerous

WARNING: TO REDUCE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT

EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.

2

IMPORTANT SAFETY INSTRUCTIONS

CAUTION:

Read all of these instructions. Save these instructions for later use . Follow all Warnings and
Instructions marked on the audio equipment.

1. Read Instructions- All the safety and operating instructions should be read before the product is operated.

2. Retain Instructions- The safety and operating instructions should be retained for future reference.

3. Heed Warnings- All warnings on the product and in the operating instructions should be adhered to.

4. Follow Instructions- All operating and use instructions should be followed.

FOR YOUR PERSONAL SAFETY

1. When the power cord or plug is damaged or frayed, unplug this television set from the wall outlet and refer servicing to
qualified service personnel.

2. Do not overload wall outlets and extension cords as this can result in fire or electric shock.

3. Do not allow anything to rest on or roll over the power cord, and do not place the TV where power cord is subject to
traffic or abuse. This may result in a shock or fire hazard.

4. Do not attempt to service this television set yourself as opening or removing covers may expose you to dangerous
voltage or other hazards. Refer all servicing to qualified service personnel.

5. Never push objects of any kind into this television set through cabinet slots as they may touch dangerous voltage
points or shor t out parts that could result in a fire or electric shock. Never spill liquid of any kind on the television set.

6. If the television set has been dropped or the cabinet has been damaged, unplug this television set from the wall outlet
and refer servicing to qualified service personnel.

7. If liquid has been spilled into the television set, unplug this television set from the wall outlet and refer servicing to
qualified service personnel.

8. Do not subject your television set to impact of any kind. Be particularly careful not to damage the picture tube surface.

9. Unplug this television set from the wall outlet before cleaning. Do not use liquid cleaners or aerosol cleaners. Use a
damp cloth for cleaning.

10.1. Do not place this television set on an unstable cart, stand, or table. The television set may fall, causing serious injury
to a child or an adult, and serious damage to the appliance . Use only with a car t or stand recommended by the
manufacturer, or sold with the television set. Wall or shelf mounting should follow the manufacturer s instructions, and
should use a mounting kit approved by the manufacturer.

10.2. An appliance and car t combination should be moved with care. Quick stops, excessive force, and uneven surfaces
may cause the appliance and cart combination to overturn.

3

PROTECTION AND LOCATION OF YOUR SET

11. Do not use this television set near water ... for example, near a bathtub, washbowl, kitchen sink, or laundry tub, in a

wet basement, or near a swimming pool, etc.
Never expose the set to rain or water. If the set has been exposed to rain or water, unplug the set from the wall
outlet and refer servicing to qualified service personnel.

12. Choose a place where light (artificial or sunlight) does not shine directly on the screen.

13. Avoid dusty places, since piling up of dust inside TV chassis may cause failure of the set when high humidity persists.

14. The set has slots, or openings in the cabinet for ventilation purposes, to provide reliable operation of the receiver, to
protect it from overheating. These openings must not be blocked or covered.

Never cover the slots or openings with cloth or other material.
Never block the bottom ventilation slots of the set by placing it on a bed, sofa, rug, etc.
Never place the set near or over a radiator or heat register.
Never place the set in enclosure, unless proper ventilation is provided.

a built-in

PROTECTION AND LOCATION OF YOUR SET

15.1. If an outside antenna is connected to the television set, be sure the antenna system is grounded so as to provide some

protection against voltage surges and built up static charges, Section 810 of the National Electrical Code, NFPA No.
70-1975, provides information with respect to proper grounding of the mast and supporting structure, grounding of the
lead-in wire to an antenna discharge unit, size of grounding conductors, location of antenna discharge unit, connection
to grounding electrode, and requirements for the grounding electrode.

EXAMPLE OF ANTENNA GROUNDING AS PER NATIONAL ELECTRICAL CODE INSTRUCTIONS

EXAMPLE OF ANTENNA GROUNDING AS PER

NATIONALELECTRICAL CODE

ANTENNA
LEAD- INWIRE

GROUND CLAMP

ELECTRIC SERVICE

EQUIPMENT

NEC-NATIONALELECTRICAL CODE

ANTENNA DISCHARGE
UNIT (NEC SECTION
810-20)

GROUNDING
CONDUCTORS
(NECSECTION 810-21)

GROUND CLAMPS

POWER SERVICE GROUNDING
ELECTRODE SYSTEM
(NEC ART 250. PARTH)

15.2. Note to CATV system installer : (Only for the television set with CATV reception)

This reminder is provided to call the CATV system attention to Article 820-40 of the NEC that provides

installer s
guidelines for proper grounding and, in particular, specifies that the cable ground shall be connected to the grounding
system of the building, as close to the point of cable entry as practical.

16. An outside antenna system should not be located in the vicinity of overhead power lines or other electric lights or power
circuits, or where it can fall into such power lines or circuits. When installing an outside antenna system, extreme care
should be taken to keep from touching such power lines or circuits as contact with them might be fatal.

17. For added protection for this television set during a lightning storm, or when it is left unattended and unused for long
periods of time, unplug it from the wall outlet and disconnect the antenna. This will prevent damage due to lightning
and power-line surges.

4

OPERATION OF YOUR SET

18.

This television set should be operated only from the type of power source indicated on the marking label. If you are not
sure of the type of power supply at your home, consult your television dealer or local power company. For television
sets designed to operate from batter y power, refer to the operating instructions.

19. If the television set does not operate normally by following the operating instructions, unplug this television set from the
wall outlet and refer servicing to qualified service personnel. Adjust only those controls that are covered in the operating
instructions as improper adjustment of other controls may result in damage and will often require extensive work by a
qualified technician to restore the television set to normal operation.

20. When going on a holiday : If your television set is to remain unused for a period of time, for instance, when you go on
a holiday, turn the television set and unplug the television set from the wall outlet.

off

IF THE SET DOES NOT OPERATE PROPERLY

21. If you are unable to restore normal operation by following the detailed procedure in your operating instructions,
do not attempt any further adjustment. Unplug the set and call your dealer or service technician.

22. Whenever the television set is damaged or fails, or a distinct change in performance indicates a need for
service, unplug the set and have it checked by a professional service technician.

23. It is normal for some TV sets to make occasional snapping or popping sounds, particularly when being
turned on or off. If the snapping or popping is continuous or frequent, unplug the set and consult your
dealer or service technician.

FOR SERVICE AND MODIFICATION

24. Do not use attachments not recommended by the television set manufacturer as they may cause hazards.

25. When replacement parts are required, be sure the service technician has used replacement parts specified
by the manufacturer that have the same characteristics as the original part. Unauthorized substitutions
may result in fire, electric shock, or other hazards.

26. Upon completion of any service or repairs to the television set, ask the service technician to perform
routine safety checks to determine that the television is in safe operating condition.

5

2、Specification

Chassis
Target Market

CRT

Color System

(TV)

Sound System

(TV)

Sound System

(TV)

System (AV)

Power Supply

Standby

picture

Terminal Rear RCA x *

matching CRT size 21" 21"
Slim CRT
PAL
PAL(BG DK I)
PAL(M N)
SECAM
NTSC
D/K
B/G
I
M
M/N
Global NICAM
German Stereo
BTSC
Sound effect
Woofer
Teletext
V-chip/ CCD
MONO(AV)
STEREO(AV)
PAL
PAL(M N)
NTSC
SECAM
AC 90-240V, 50/60Hz
AC 180-240V, 50/60Hz
AC 160-240V, 50/60Hz
AC 110, 50/60Hz
AC108V-132V 50/60Hz
<1W
<3W
<4W
<6W
<9W
<10W
<12W
Comb-f for NTSC (1H delay)
Comb-f for PAL/NTSC (4/2H

delay)

Rear SCART(Single)
S-Video (Rear or Side)

SY33 SY33

S.America APAC/Russia

√√

★√

√

★√

√

★√
★√

★√
√
√

★√

★√(2for1)

√√

√√

AC90-270V AC90-270V

√√

√(built-in MCU) √(built-in MCU)

★2 input/ 1output ★2 input/ 1output

★√ ★√

★√(2for1)

YPbPr
HDMI

Language

digital module DVB-T / ATSC

★√ ★√

English/Portuguese/French/ Spanish

(1)English/Russian/Arabic;

(2)English/Vietnamese/Thai；★

Thai Bilingual

3、Alignment Procedure

Method for Entering Factory Mode：

a. Production mode: Press the key [Fac] in remote control to enter or exit factory mode(But only

display 4 pages);

b. Engineer mode: Press key [DISPLAY] to display channel information（Setup for display picture

on bottom left of screen, press the number key [6][1][5][8] ;

c. Display “--PRODUCT--”，then press the key [MUTE] two times，the factory menu on the screen 。

The number on top right corner of factory menu is page number of factory menu. Press the key
[CH+/-] to adjust curser up or down。Press the key [VOL+/-] to change the value。When choose
the first top line, press [VOL+] / [VOL-] to choose the menu page。

d. Press key [sleep] to display factory menu in production mode. Please choose next page when display

factory menu。

e. Press key [0] to be shifted to one bright line status in production mode,. Press key [0] again to return factory

menu.

Relevant key number for one bright line：

[1] RB+ [2] GB+ [3] BB+
[4] RB- [5] GB- [6] BB-

Factory Service Menu Index:

*** PAGE 1 ****** Init Range

V.POSITION/50 19 0…63
V.POS SHIFT/50 0 0…15
V.SIZE/50 79 0…127
V.LIN/50 23 0…31
V.SC 17 0…31
OSD-V-START/50 0 0…3
OSD-H-POS 20 0…127
CHANGE PRO.

*** PAGE 1 ****** Init Range

V.POSITION/60 19 0…63
V.POS SHIFT/60 0 0…15
V.SIZE/60 79 0…127
V.LIN/60 23 0…31
V.SC 17 0…31
OSD V.START/60 0 0…3
OSD-H-POS 20 0…127
CHANGE PRO.

*** PAGE 2 ****** Init Range

H.PHASE/50 15 0…31

H-BLK L 0 0…7
H-BLK R 3 0…7
H-SIZE 0…63
H.SIZE COMP/50 0…7
TRAPE/50 0…63
PARABOLAO/50 0…63
U.CORNER TOP/50 0…15
U.CORNER BTM/50,60 0…15

*** PAGE 2 ****** Init Range

H.PHASE/60 15 0…31
H-BLK L 0 0…7
H-BLK R 3 0…7
H-SIZE 0…63
H.SIZE COMP/60 0…7
TRAPE/60 0…63
PARABOLAO/60 0…63
U.CORNER TOP/60 0…15
U.CORNER BTM/60 0…15

*** PAGE 3 ****** Init Range

RB 127 0…255
GB 127 0…255
BB 127 0…255
R-D 90 0…127
G-D 12 0…15
B-D 90 0…127
S.B 80 0…127

*** PAGE 4 ****** Init Range

PROD.AGING OFF OFF/ON
RF-AGC-DELAY 16 0…63
CONTRAST/50 60 0…63
COLOR/50 20 0…63
SHARP/50 8 0…31
TINT/00 30 0…63
EW-COR.SW 1 0/1
CLEAR INFO NO NO/YES

*** PAGE 5 ****** Init Range

OSD CON. 3 0…7
FULL-OSD CON. 2 0…7
OPT-AV 2 0…3

OPT-SVIDEO YES NO/YES
OPT-DVD YES NO/YES
OPT-AV3 NO NO/YES
AMERICA N/S USA/（N/S）
TUNE-SPEED 3 0…3
CH6 BAND 0 0/1

*** PAGE 6 ****** Init Range

OSD THEME 0 0…7
OPT-LOGO 0 0/1
HALF TONE 1 0…3

*** PAGE 7 ***CHROMA Init Range

COL-AUTO ON ON/OFF
COL-NTSC ON ON/OFF
COL-PAL/M ON ON/OFF
COL-PAL/N ON ON/OFF
C.TRAP ADJ/PAL 7 0…7
C.TRAP ADJ/NTSC 4 0…7
C.BPF ADJ. 0 0…3
C.VCO ADJ/NTSC

*** PAGE 8 ***FM Init Range

DEEM.TC 1 0/1

FM.GAIN

4 0…7

0 0/1

INIT EEPROM

*** PAGE 9 ***Other Init Range

PRO.MUTE OFF ON/OFF
BRI.MAX 63 0…63
VOL/01 0 0…127
VOL/16 61 0…127
VOL/36 103 0…127

*** PAGE 10 ***ON/OFF Init Range

AC-POWER ON LAST LAST/OFF
ON-TV/AV LAST TV/LAST
ON-DELAY 1 0…3
ON-SEARCH NO YES/NO
OFF-V.DELAY 0…7

NO YES/NO

*** PAGE 11 ***PIC. Init Range

BLK.STR.START

BLK.STR.GAIN 3 0…3

*** PAGE 12 ***PIC. Init Range

BRT.ABL.DEF 1 0/1
MID.STP.DEF 1 0/1
BRT.ABL.TH 7 0…7
CORING GAIN 0 0…3
WPL OPE.POINT 2 0…3
Y GAMMA 2 0…3

DC.REST

COL.KILLER OPE. 4 0…7
RGB TEMP SW 1 0/1

*** PAGE 13 ***PIC. Init Range

SH ADJUST 0 0/1
B-Y/DC 12 0…15
R-Y/DC 12 0…15
B-Y/DC.DVD 9 0…15
R-Y/DC.DVD 9 0…15

*** PAGE 14 ***SYNC. Init Range

AFC GAIN/GATE 1 0/1
FBPBLK.SW 1 0/1
VSEPUP 0 0/1
VBLK SW 0 0/1
V.COUNT AUTO YES YES/NO
V.COMP 3 0…7
SYNC.SEP.S 4 0…7
H.FREQ/ES 32 0…63
VCO FREQ.IF/ES

*** PAGE 15 ***C.DEMO Init Range

G-Y AMP 8 0…15
G-Y ANGLE 0 0/1
R/B GAIN 8 0…15
R/B ANGLE 8 0…15
PAL APC SW 0 0/1
OPT-V.PROTECT OFF OFF/ON

V.PROTECT TH.

0 0…3

2 0…3

31 0…31

OPT-ABL.P OFF OFF/ON
ABL-LOW LIMIT 63 0…63

*** PAGE 16 ***IF Init Range

OVER.MOD.SW OFF OFF/ON
OVER.MOD.LEVEL 2 0…15
PRE-SHOOT ADJ 0 0…3
OVER-SHOOT ADJ 0 0…3
VIDEO LEVEL 7 0…7
VIDEO.LVL.OFFSET 2 0…3
S.TRAP ADJ 4 0…7
IF VCO ADJ 2 0…3

4、Block Diagram

Antenna

AGC

IR1001 Key Board

Tuner

AV1
S V ideo Y

AV2
YCbCr
AV out

Scart
signal

Q101 IF
Preamplifier

IC001
24C16 EEPROM

C

Scart Audio

AV1 Audio

R/L

AV2 Audio

R/L

R/L

Z101
SAW
LBN3
383

48 49 51

63
64

I2C BUS

31
32

46
45
54

MUTE

61

26 29 36 30

IC201
LA76933
IFamplifier/ Video detection
/Sound detectionj/ Y&C
Separation/ Color decode/
Base color matrix/ Sync
separation/ display process/
AV switch/ MCU/ OSD

52

STB BY

5

12
IC901
4052
Electron
Switch

12

13
14

Q502/Q504/
Q506 V i deo
Preamplifier

IC301

17

LA78041
V-amplifier

44

21

Q401 T401 Q402

15 EW

AV Audio out

3

13

IC601
LA4235
2 Audio

8

12

Amplifie

V SCAN

FBP

FOCUS

H SCAN

SCREEN

T402
FBT

4/5 11 10

±14V 220V 6.3V

HV

5、Circuit Flow Introduction

1)、Chassis summarize

The main chip of SY33 chassis adopt IC LA76933 of SANYO company ,audio power
amplifier adopts IC LA42352,power supply adopts IC STRW6553, and vertical scan amplifier
adopts IC LA78041.The chassis has low cost and steady function, it has been adopts for
25M63,21M63 model.

2)、Base features

The unit TV supports PAL/DK.I,AV supports PAL/NTSC system, in 2XAV,1x S-video

3)、Unit Signal Flow Introduction

SY33 chassis circuit includes tuner, IF ,SAWF,LA76933 H/V scan circuit ,AV board, side AV
board, keypad board, USB board, power board. audio power amplifier circuit and power supply
circuit etc. The main ICs are LA78041,LA42352,HPC922-C,L7809CV,L7805CV, LA76933,
HCF4052 IC etc.

1）TV signal flow

RF from antenna enters tuner to be processed ( RF being inverted IF), and IF from pin11 of
TU101 passes R106 ,C110 to Q101 IF preamplifier .

After amplifying, IF signal enters pin1 of Z101 to filter and separate SIF and PIF via pin4 and
pin5 of Z101 into pin63 and pin64 of IC201(LA76933) to process PIF .

There are two ways output signal of process IF amplifier:

One is video signal, from pin60 of IC201 , after R227,R228 adjustment ,it is sent pin56 of
IC201 to process demodulation of picture.

Another way is sound signal, from pin5 of IC201 and passes C260 coupling。 The sound
signal is sent to pin1 and pin9 of IC901,after IC901 choosing, signal from pin3 and pin13 of
IC901 is sent to pin2 and pin4 of IC601 to process sound power amplification. After amplifying,
The signals from pin8 and pin12 of IC601 is sent to L/R speaker.

2) AV signal flow

AV1 signal process circuit.

Video signal of AV1from pin1 of P901 enters to pin46 of IC201 to decode process.

Sound signals of AV1from pin2 and pin3 of P901 input is sent to pin5 and pin 14 of IC901 to
choose , after being choosed, the signal flow same as TV sound.

AV2 signal process circuit.