Proto E7B with QSI sound not working

[selector]

If it reset properly and runs, then the tether plug or receptacle/pins/one wire are defective, or the speaker and its wires need testing, or the onboard amplifier is toast.  More skilled people will correct me, but I've had failures in decoders that would make noises, even increase chuff rate in response to throttle inputs, but they wouldn't budge no matter what I did.  And the other way as well...they move, but won't make a peep. One was a LokSound, the other a QSI.

[drgwcs]

I am having an issue with a Proto E7B unit that has a QSI decoder in it that is not putting out any sound.

Recently a dear friend and member of our club passed away and his widow graciously donated some of his equipment to the club. I had volunteered to go ahead and program them on my NCE at home (a different one was being stubborn on Digitrax) I programmed (one at a time) both the E7A and the E7B to the same address to run together. Both units are QSI equipped. I have sound and everything fine on the A. The B on the other hand was silent- so I figured they just relied on the A for the sound. Then I popped the top and found hmm- this thing has speakers and a QSI decoder- but no sound. I figured the easiest thing was to do a reset with the reed switch (it must have worked as it reset to address 3) but still no sound. It runs find and responds to commands but doesn't have sound. I tried the f8 too no difference. Any thoughts- is there a CV that is set to default off? Skimmed the QSI manual on it online but found nothing (could have missed it that thing is the size of an encyclopedia) Any thoughts?