Sanyo LCD-32XR8DA, Service Manual

11 

Working principle analysis of the unit   

1. PAL/SECAM signal flow: 
Antenna reception PAL/SECAM signal will be send to tuner TDA1616, which contains frequency 
turning, HF and IF amplifier circuit and is controlled by master control IC MSD109 (comprises CPU) 
through I2C bus. The analog IF signal via intermediate frequency amplifying, video SAW filter 
K3953 and audio SAW filter K9656 to input to analog demodulate IC (IF) R2A10406NP, after 
demodulating and output standard video signal TV-CVBS and sound IF signal (SIF). 
TV-CVBS will send to the master control IC MSD109 to video decode, deinterlace and scale, then 
output LVDS level drive for panel display. 
The sound IF (SIF) will be fed into MSD109, after demodulating, pre-amplifying, bass adjusting and 
volume control, the sound signal will separate into L/R channels and input to earphone amplifier 
BH3547F amplifying, then output two ways. One way will be sent to earphone, another will be sent 
to digital sound amplifier R2A15112FP amplifying then sent to speaker. 
   
2. DVB-T signal flow: 
Antenna reception DVB-T signal will be sent to tuner TDA1616, after frequency tuning, HF 
amplification, IF amplification and SAW FILTER, output IF signal to demodulation chip CE6353, via 
QAM demodulation, fed to MSD109 for information source decoding in the format of standard serial 
TS stream. 
HD video signal via decoding to A/D conversion and OSD superposition, at last output LVDS drive 
level for panel display. 
HD audio signal via decoder built-in MSD109, resumed to multi- channel sound of Dolby AC-3. The 
audio signal will be sent to back end to perform bass adjustment and volume control, then it will 
separate into L/R channels and input to earphone amplifier BH3547F amplifying, then output two 
ways. One way will be sent to earphone, another way will be sent to digital sound amplifier 
R2A15112FP amplifying then sent to speaker. 
     
3. AV/SV signal flow 
SV signal and the first path AV signal switch automatically via S-terminal socket, the signal and the 
second path AV signal will be fed to MSD109 to perform video decode, deinterlace and scale, then 
output LVDS drive level for panel display.   
Audio signal from AV/SV via matched resistance is fed to external audio switch HEF4052 to switch, 
then it is directly sent to MSD109 to bass adjust and volume control, the sound will separate into L/R 
channels and input to earphone amplifier BH3547F amplifying, then output two ways. One way will 
be sent to earphone, another way will be sent to digital sound amplifier R2A15112FP amplifying 
then sent to speaker. 
 
4. PC/YPrPb signal flow 
PC and the second path YPbPr signal are switched via external switcher PI5V330, then the signal 
and the first path YPbPr signal will be sent to MSD109 A/D conversion, output R/G/B of 24 bit to 
back end module to digital decode, image scale and OSD superposition, then send to LVDS level 
drive for panel display.   
Sound signal of PC/YPrPb via matched resistance and a-c couple are sent to MSD109 to bass 
adjust and volume control, the sound will separate into L/R channels and input to earphone