Friends
Can any one explain how video output from single chip tv IC is
formed. I have seen two to three typical problems in Samsung TVs, in
which no video , sound normal when screen volt is increased retrace
lines appears. Cathode volt is full. no video drive from IC. All IC
voltages are ok, screen volt Ok, focus volt Ok, Final anode volt
ok.The single chip is TDA9381. Initialy it takes few second for
picture to appear for a good TV, till that time video out volt from IC
remains low.
In this defective TV, picture appears for few second after initial
delay. There after picture appears sometimes when voltage is measured
on RED cathode.What is this phenomenon. What are the interlocks for
picture
to appear. In some TV if vertical fails video output goes to low. And
in some ABL causes video to low. So how to diognise this type of
problems?
.
