EH Small Stone problem...

[arielfx]

this effect was returned to me by a customer and the bypass mode works well (you can hear the guitar) but when you want to switch the effect in it cuts off any signal and that's it.... no LED no nothing and I have no ideas what is wrong in here.

how can i check if he burned something with wrong polarity?

[petemoore]

By taking the OA pin voltages readings from ground. See if any of those look 'funny'.
 Then proceed to the debugging page and task out some of those techniques on it.

[Rick]

Test the switch first, it may save you a lot of time. I've had this problem twice and it did turn out to be the dpdt switch in both cases (half of it was bad). Hope it is this simple in your case.