[MrFixr55]

There are many common reasons for a radio to not play but the phono section to work.  For a transformer powered set, any tube in the radio section (RF Amp, Convertor, IF Amp, detector that is not part of the 1st Audio tube with an open filament would fail to play.  Any open oscillator coil or IF transformer would do the same thing.  If the radio / phono switch was bad, this could also happen.  I have had RCAs and GEs from the mid-30s with transformers that bought the farm spontaneously.  

I don't know if the 6X5 is guilty of commonly shorting, as it had an indirectly heated cathode, unless the insulation between the heater and cathode broke down.  I had sets with 80s and 5Y3s, especially those with the "tent" style filament that if the filament opened and touched the plate, it would short, possibly taking out the transformer.

I had a Philco console AM / SW radio / phono (possibly a 46-1226) as a kid.  I had it on and while in the shower the 5Y3 failed and took out the transformer, filling the house with smoke.  Mom totally freaked, and made dad make me throw out the radio on the spot.  because of this, when I restore a radio with an old 80 or 5Y3, I put silicon diodes in series with the leads from the transformer to the plates of the rectifier to prevent the recurrence of the issue (Ms. Fixr would make me throw the set out, but it would be rescued).

BTW, smoke is what makes electronic, electrical and some mechanical devices work.  I know this from the scientific method.  When you let the smoke out, the device stops working.  Therefore, by deductive reasoning, smoke is what makes these devices work.