This was a tough cookie! It didn’t make any sound when engaged.. so I started looking for bad connections and found many of them! Input/Output/dc jacks were badly soldered and one pcb trace was broken. Resoldered bad joints and jumpered broken traces. Slowly it started to come back alive and all chips measured ok! It sounded like a rotovibe but made occasional ticking sounds when engaged.. Again going through the circuit and poking around to find a hint to fix the problem. Then I noticed the led indicator part of the pcb had lost proper ground connection on one point! I just jumpered the output jack ground to this point and all problems were gone :) Tommi of Ghost Brigade is using this pedal regularly.