Report "There is no amplified sound through the fishman Prefix Pro Blend on my classical guitar since I changed the strings and installed a new battery. The led light comes on, briefly, though. It doesn't work on either of my amps. Previous to this the led light was permanently lit and the sound was "breaking up" (cracking).( New battery needed, I assumed ). I've played a lot outdoors and thought maybe that damp was the problem. I've also opened it up and can't see any clues. Also re-adjusted the bridge. The pick-up seems in place"