communicated signal between ES7010 and 64M SDRAM.
（
2
）
Test the 8
channels of digital video signal between SAA7114 and ES7010.
（
3
）
Test the
communicated signal between WM8739 and ES7010, the relevant resistance is
RN16.
（
4
）
Test the output of ES7010 to LVT244B and the data buffer which
composed with LVT374. Test the 8 channels of digital video signals, the relevant
resistances are RN20, RN24.
（
5
）
Test the digital video data signal of data buffer
to ISP2064 and ES6128.
The mainboard and output board have composite output, S-video, RCA video
output,. Audio output has 5.1 CH audio output, optical , coaxial digital audio output.
It includes 5.1 channel audio DA circuit, audio amplify circuit, optical and coaxial
output circuits, SCART audio/video output circuit. SCART SCART circuits is
composed with three SCART controlling signal lines and one audion controlling
circuits. It can switch different AV situations of TV with SCART port by voltage
level’s high and low. Three SCART lines produce high and low voltage level signal
by LVTH273 of mainboard, it can control the audion. Optical and coaxial circuit is
built by the digital audio signal which outputted by mainboard then amplified by
VHCU04, at last it will output at the coaxial jack. The video output circuit is mainly
about mainboard output all kinds of video signals, these signals can be outputted
on all kinds of video output jacks after matching the circuits. The mainboard
outputs digital signal and transferred to 6 channels audio by PCM1606 DAC
transfer circuits, and then the 6 channels ‘s audio would be output after amplified
by amplified circuits. This process can build 5.1 channel output circuit. The main
trouble displays that there is no sound from 5.1 channels, or no audio output from
one group of 5.1 channels, or there is no audio signal from optical and coaxial. If it
takes troubles, you should analyze the troubles from back to forward step by step.
If it has no audio output, you should check RC4558 amplifier and the process of
digital audio to simulate audio.
Ⅴ
.Power supply board troubleshooting flow
