I had an Ebow for a few years - I love how these things sound. However, mine spontaneously quit on me one day. I had taken excellent care of it - never dropped it, never knocked it around, always put it back in its little felt scrotum. The little blue LED still comes on, but the thing won't produce sound anymore.
A friend's Ebow shit the bed, too. He took it apart (a nearly impossible task since there are no screws - the thing is filled with hot glue to (a) keep it shut and (b) keep prying eyes from reverse engineering the circuit board. I fixed his problem - it was just bad soldering on some pins.
Inspired by the easy fix of my friend's Ebow, I ripped mine open, only to find the solder points in tact. The problem must be on the circuit board, buried beneath glue.
I went on the lousy Ebow site - I couldn't even find contact information. It's a fucking crime that they charge almost $100 for this piece of shit. The construction is just cheap and awful. I'm not going to buy another; fuck them.