Just a thought about the electrolysis. Did the "coin" bubble and all that? If not, there could be something wrong with the set-up:
- the polarity could be reversed (if you use it routinely, that's probably not it)
- the unit could be DOA did you check the voltage?
- Not enough electrolyte in the solution, pump up the lemon juice maybe
- lastly (and most probable) the clip on the coin is not making good electrical contact (maybe the item isn't that conductive to start with.
Just some things to look at.
Daryl