I pulled my phase 90 out of retirement today and it's not working. I put in a brand new battery but when I stepped on the switch it didn't go on; no effect, no LED or anything. And sound only comes out of my amp when the switch is in one of the two positions. Is there a connection problem somewhere maybe? I don't know much about electronics, so does anyone know what might be causing the problem?

It could be anything, really. Maybe the battery snap is broken... or not. Might be a loose solder on one of the jacks... or not. You can open it and see if there something loose or broken, but really, if you know nothing in electronics, bring it to a tech.