The picture tube or CRT is not the problem, and yes this set is fixable. What has happened is that the vertical deflection
circuit has malfunctioned. More precisely
the vertical coupling capacitor has malfunctioned (The pooping
sound was the capacitor exploding).
Open up your TV (take the back off and unplug the set), and look for the damaged capacitor, it will look puffy or if it has exploded.
To fix this problem you will need the schematic diagram for the TV (can be found at www.servicemanuals.net
). Then you will need a multimeter to measure the DC voltages on the vertical output circuit, and finally an oscilloscope to measure the waveforms at the vertical output circuit and the input to the vertical windings of the deflection yoke transformer.
Now what you should basically find is a sawtooth wave at 60Hz which is the drive for the yoke transformer. However since the coupling capacitor is bad you will have the wave at the output of the vertical output stage, but not at the input of the yoke transformer. Use the schematic to find the value of the capacitor
that has malfunctioned.
I hope this helps,