Transistor Radio, TV or CB- No Audio

When you don't have audio, first off don't just rip it all apart.

 Check the headphone jack. More specifically the switching contacts on the headphone jack.

I can't remember how many times I found dirty or bent contacts on the headphone jack.

 Use some cleaner on the contacts and plug into it at least 6-8 times to verify audio is back at the speakers.

If bent contacts, just replace with a good quality jack- like Switchcraft or similar. 

You can also signal trace the jack. Sometimes just plugging in & out of the jack will restore function, but use cleaner.

The contacts points can get tarnished, dirty, or nicotine smoke covered. 

I don't often see this anymore but it was real common in dirty houses, open fireplace houses, and smokers homes.