I replaced Q7 with no change, unfortunately.? It did look damaged on closer inspection - One of the corners looked like it had chipped off somehow.
When I'm referring to Ch 1 and Ch 2, I'm referencing the audio channels in the Test Equipment menu - Page 102 in the manual.
I looked at the schematic, and on a hunch checked the volume pot.? Not sure how, but somehow it seems to have gone out - I shorted two of the volume pot pins to check and got a tone.
Next time I go out I'll get another volume pot and see if that resolves everything.
Thanks!