I built a Dr. Boogie, turn it on, LED works, but no sound, bypass works as well. I try to troubleshoot for a week, quit, and left for 8 months to university. I come home for the summer, look at the pedal again, and realize I labeled the input and output jacks opposite of each other. Switched the cables, the pedals worked fine. I took some time off of building pedals after that.