Fixing sound on a 1978 RCA B&W set

[BenM86]

Recently picked up this small B&W RCA at an estate sale too add to the collection. It's in nice shape and has a really great picture, super bright. But the sound is completely dead. No sound at all, not even from channel fuzz. I looked inside and there is nothing blatant wrong, no obviously blown caps, and the wiring to the speaker all looks intact and ok. I'm not at all familiar with TV's of this age though. Is this something that can be fixed? Where would I start looking? Thanks!!