[Radioroslyn]

My best guess for low volume and somethings not working well is that the power supplies is dying do to bad filter cap and bypass cap throughout the tuner and amp chassis. If you continue to operate it in this condition it can damage expensive parts and worst case catch fire. Servicing this set is somewhat of a fairly large undertaking as there are probably 20-30 caps to replace some resistors and an alignment to do afterwards. I'm not sure what your skill level is for this sort of thing is but wouldn't catogorize it as an entree level project. No ofence just being honest. You might luck out and may have mostly disk caps rather than the older foil/paper style.

GL.