Ok, let's try a little component level troubleshooting. I don't know what you have in the way of test equipment but let's just say all you have is an ext speaker that you can use as a tester. If the TA7222P is producing audio you should see or hear that audio at the coupling capacitor C118 it's a 470 with the positive pin connected to pin 9 of TA7222P. At this junction, you should have audio. So if you touch a lead of the speaker at the negative terminal of C118 with the volume up you should have noise of some kind and it should be pretty loud unsquelched. Just be careful use probes from a DVM and attach them to the extension speaker plug you could isolate the speaker with a small .01 cap while grounding the speaker wire. I only went through all this because I don't know if you have an audio signal tracer or a scope or even an auto-ranging ac meter. The point is you have poked and hoped by replacing parts maybe this is a better approach. This will at least determine if there is audio being produced by the TA7222P. with an amplified audio source such as an audio signal tracer or scope, you could also check to see if there is audio being delivered to the TA7222P at pin 4 I believe if memory serves me I have worked on literally thousands of these and other radios over the years and sometimes get them mixed together. I included a simple audio amp that could be used as a tracer and guess what it's made with a TA7222P!...
Vintagetech52 alias Oldtech03
