The conversion chip is powered by seperate power from the transfomer + -- volts
here is I believe what your conversion chip # is stk392-110t and here is the NTE specs.
http://www.nteinc.com/specs/7100to7199/pdf/nte7178_81.pdf
you can use the specs. to check voltage pins, ect.. ,if that is the numbers.
to see if the chip is faulty then check resistors, caps , and voltage to the chip , a pr or fuse may have blown for the - and + voltage to the chip. if it is bad it would be wise to replace the vertical deflection chip as well ( hopefully yours is still ok) , because of the vertical control in the conversion chip.
you can also check for the power on the wires from the CRT board that comes from the flyback transformer ( NOT the HIGH VOLTAGE wire ).
also after you have unplugged the tv and dicharged the flyback to the chassi ground you should check the components on the crt ( cathode ray tube ) board for any bad measurements of the components.
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No. It all began when it just shutdown. The screen would go completely black. We would turn it off, and in a couple of hours, we turn it back on and it was up and running again. We kept on using it, until I had time to look more into it. I found a video cable that came off from the jack. I replace this cable, and I thought it was fine. But, a then started to hear this pop, and the screen would go off again. We would turn it off again, and it would come on again for few hours when it would go off (screen black). A couple of days later, I turned it on again, and I would only see the thin line across on the middle of my screen. I check a couple of sites on the web, and said that it was my vertical IC and some caps around it, but I did that, nothing. It still the same. Is there something that I can do with the CRT?
At the moment, I see a suspicious cap near the flyback transformer. I just noticed that it has a black chalky substance on the side. I'll replace this next. I have checked several resistors around the area, and they seem check okay. The fuses look good, at the moment I'm thinking of replacing the cap and see what happens. Do you guys think that would have cause the problem in the first place?
The thin, line appears across the screen when I turn on the t.v. and it's about 1/8 of inch thick. I'm not familar with the convergence chip. Do you guys know what part number it would have or where it would be located?
I'm sorry I can provide an exact model number cause the labels that were on the back of the set have fallen off. I just remember that it was built in 1989 because I check it the label once, and that's when I graduated from high school...
I just noticed a number on the inside of the t.v. case. It's CF3254H, the letter "H" is pretty faint, but that's what I think it could be. Does that help for model number?
whoops , if the line is from top to bottom vertical is ok if from left to right then vertical is not
have you checked the fuses by the trans former that supply voltage to the convergence chip?
also could you look to see what model it is?
if the vertical line goes all the way across then its not the vertical deflection IC .
have you first checked for any indications of a burnt component, resistors by convergence chip, flyback transformer voltages?
have you looked at the CRT its self?
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