TCL SY33 chassis – TCL25M63 TCL21M63 - slim CRT TV – how to enter service mode, circuit diagram, TEA1506 IC controlled SMPS schematic
Used ICs:
21C16 (Memory), LA76933 (Syscon: Chroma jungle), BCK3532(FBT),
TEA1506P(SMPS control), LA78041(Vertical scan output), LA42352(Audio
output), AS1213 (Remote control decoder: in the remote handset),
4052(Input selector)
Method
for Entering Factory Mode (Service 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 courser up or down
Press
the key [VOL+/-] to change the value.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 courser up or down
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
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.
TEA1506P IC based SMPS circuit diagram
The unit TV supports PAL/DK.I,AV supports PAL/NTSC system, in 2XAV,1x S-video.
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
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,
Click on the circuit diagrams to magnify
The signals from pin8 and pin12 of IC601 is sent to L/R speaker.
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 choose, the signal flow same as TV sound.
AV2 signal process circuit. Video signal of AV2 from pin4of P901 is sent to pin54 of IC201 to decode process.
Sound signals of AV2 from pin5 and pin6 of P901 is sent to pin1 and pin 12 to choose signal,. After being chose, the signal flow same as TV sound.
Sound signals of AV1from pin2 and pin3 of P901 input is sent to pin5 and pin 14 of IC901 to choose , after being choose, the signal flow same as TV sound.
AV2 signal process circuit. Video signal of AV2 from pin4of P901 is sent to pin54 of IC201 to decode process.
Sound signals of AV2 from pin5 and pin6 of P901 is sent to pin1 and pin 12 to choose signal,. After being chose, the signal flow same as TV sound.
High-Definition
signal flow.
Y signal from pin7 of P901 enters pin48 of IC201 to process video.
Cb signa from pin8 of P901 enters pin49 of IC201 to process video.
Cr signal from pin9 of P901 enters pin51 of IC201 to process video
Y signal from pin7 of P901 enters pin48 of IC201 to process video.
Cb signa from pin8 of P901 enters pin49 of IC201 to process video.
Cr signal from pin9 of P901 enters pin51 of IC201 to process video
Sound
signal from pin27 and pin28 of IC201 enters pin6 and pin13 of IC601 to be
amplified and be sent out form pin8 and pin12 of IC601
Mute
control
Pin30 of IC201 sends mute control signal, and passes D002 to connect base of Q602,controls the Q602 ON or OFF, the pin C of Q602 connects pin5 of IC601 to control mute normal working .When Q602 off, pin5 of IC601 is high level. So pin8 and pin12 of sound signal output to speaker, when MCU sent mute signal of high level,Q602 ON, it lets the pin5 of IC601 is low level to shut down the sound signal of pin8/pin12 of IC601, the mute is working.
Pin30 of IC201 sends mute control signal, and passes D002 to connect base of Q602,controls the Q602 ON or OFF, the pin C of Q602 connects pin5 of IC601 to control mute normal working .When Q602 off, pin5 of IC601 is high level. So pin8 and pin12 of sound signal output to speaker, when MCU sent mute signal of high level,Q602 ON, it lets the pin5 of IC601 is low level to shut down the sound signal of pin8/pin12 of IC601, the mute is working.
TU101
is a common tuner. The RF signal is processed by tuner inside circuit disposal
:high frequency amplifier, mixing, high frequency demodulation, AGC, AFT, PLL.