Service manual

SERVICE MANUAL LS07 chassis

This chapter mainly introduces analog signals processvideo intensify process

TV system control processTV supply system of the Europe LCD TV.

One Analog signals process

1. IF/RF process

Completed by TAF-C21P1 RF tuner, output IF signal.

The Function of RF tuner is below:

Pin symbol function

1 AGC Auto gain control voltage

2 TU The TV do not connect

3 ADD ground

4 SCL I

C busclock 

5 SDA I

C busdata 

6 BM +5V power supply

7 BM +5V power supply

8 NC Not connected

9 BTL +32V power supplyform 032V tune voltage

10 NC Not connected

11 IF IF signal output

2. Image and sound process

UOC chip receives the IF signal seperated from SAW , detect and decode.

Output RGB color analog signals from the 858687 pin respectively. Output

the main channel LR audio signal from 6061 pin. Output earphone channel L

R audio signal from 6263 pin. additional, Part number U7,TDA9178 complete

the enhancement of quality of the picture ,by the output 747576 pin Of UOC

and the input 707172 pin, combined with UOC to form a loop circuit.

Further, AVS-VideoYC signal of inside DVD(some types of TV have not) is

also decoded inside of UOC chip, switch internal UOC with TV input and output

a RGB color analog signal, send it to back-end process.

Two Digital signal process

The analog RGB signal output from UOC and RGB signal output from DFP are

switched and selected by a PI5V330A,input it into the 656360 pin Of MST518.

The RGB signal output from computer and HD-YpbPr signal are switched and

selected by another PI5V330A,input into the 757270of MST518.This two

channel RGB signal are switched inside MST518,then AD converter, video

format transition, at last output digital color signal which is suitable for TFT drive

circuit. MST518 process the pixels ratio converting of input video signalthe

image auto optimization process, then process memory bufferscalerchroma

matrix circuitchroma look-up tablechroma space gain, etc. Output

corresponding standard physical resolution digital color signal and

corresponding sync, clock signal to TFT, control the TFT to display image

correctly.