Here's an idea (not a proven solution) - if you haven't thrown your ENV3 away by now...
On mine, there appears to be some foil tape (or at least silver tape) going from the speaker to the LCD edge. If that is conductive tape then, maybe, that is why your speaker isn't working.
Just an idea.
I'll include a picture if I can figure out how - though my picture quality is poor.
Here's an idea (not a proven solution) - if you haven't thrown your ENV3 away by now...
On mine, there appears to be some foil tape (or at least silver tape) going from the speaker to the LCD edge. If that is conductive tape then, maybe, that is why your speaker isn't working.
Just an idea.
I'll include a picture if I can figure out how - though my picture quality is poor.