I have completed the following (in order) this past weekend:
1) Watched your video (excellent - thank you!)
2) Read "the Other Tim's Set-up and Instructions" (again excellent and thanks)
3) Downloaded the newest updated software version for my HC-2
4) Downloaded the newest updated software version for my LM-2S
5) Downloaded two new sound files - Bronze Bell and Sanding.
6) Updated new software versions on my HC-2
7) Copied new sound files from the HC-2 to the loco.
Switched out the 6-pin harness (with the speaker attached) to another LM-2S and heard sounds (thus eliminating the speaker or the harness as a problem).
Still no sound.
Everything else works perfectly.