First I had horizontal lines near the top of the screen for about one month. Now the image has collapsed to the bottom 1/10 of the screen or just a flickering line at the bottom. Audio also quit at the same time. I have some background in digital systems and circuit board design. Can this be fixed? I would guess a internal power supply toasted some IC's. If you would be willing to give me a hint, or even better, component identification or location I'm sure I can put humpty-dumpty together again. It would be greatly appreciated.
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Hello! You have vertical collapse. There are bad solder connections at the vertical output IC. I have repaired MANY panasonic tv's like this. Very easy to repair if you have any soldering experience. If soldering does not fix the problem you need to replace the vertical IC. Good luck
This is what is known as frame collapse - which means there is no vertical deflection applied to the tube.
Please do not continue to watch the set in this condition as it may burn a horizontal line in the middle of the screen.
The most likely cause is either bad solder connections to or failure of the frame vertical output IC.
Please rate the assistance I have given - I hope it is useful. If you call a serviceman and tell him its frame collapse as this type of repair is not for amateurs - voltages in television receivers can kill.
The several thin white lines at the top of the screen is the warning that the vertical output IC is not getting the boost voltage it needs to run correctly. The IC cannot operate for long like that and shorts out inside, which is when the vertical collapses altogether and you get the thin white line through the center of the screen. The good news for your son is that he had nothing to do with that, and it has nothing to do with the cable F connector. The set needs to be serviced by an experienced tech who will restore the boost supply and replace the vertical output IC, and when I do that I charge $75 but techs in your area will vary, so be sure to ask around.
Assuming this line is across the screen horizontally (side to side), this means the vertical deflection circuitry is dead. In late model sets, there is a Integrated circuit package which drives the vertical yoke coils. Possible defects: the I.C. itself, bad solder connections where it solders to the board, missing voltage source to this I.C. (often around +24 volts), or a bad electrolytic capacitor in the associated circuitry. This latter often results in a non-linear picture, or less than full deflection condition, rather than a thin line only.
It is possible lightning caused this problem, (I've seen some rather illogical damage from lightning ) perhaps it produced enough of a surge to pop the I.C. or a fusible resistor in that voltage source noted above.
this symptom is what we called vertical fold-over. vertical fold-over is characterised by a white horizontal bar on the bottom or top of the raster due to the concentration or compression of the trace lines. it an image is present, the bottom or top portion is fold over. this is caused by a vertical deflection current with poor linearity, which compresses the trace lines at the bottom or top of the screen. this symptom is is caused by a defective sawtooth wave genetator circuit, or improper biasing or defective feedback circuit of the vertical drive or vertical output transistor/ic. the negative feedback circuit in vertical deflection circuit compensates for the linearity of the trace portion of the sawtooth wave. a decrease in the capacitance of the sawtooth generator capacitor is usually the trouble. but if you do not understand anything what i have written here, better bring it to a qualified tv technician for your own safety also. good luck!