I recently bought this: http://www.ebay.co.uk/itm/Demeter-TRM-1-Tremulator-Pedal-/230899314469?_trksid=p2047675.l2557&ssPageName=STRK:MEWNX:IT&nma=true&si=eJ1AUWCkb72hjN9tKlwtmohZ%2B6s%3D&orig_cvip=true&rt=nc

It arrived the other day and I gave it a go just now but no sound comes through when engaged. The light comes on and you can hear a very faint throb of the tremolo so that part of the circuit obviously works but no actual guitar.

When disengaged, the guitar sound comes through fine.

Any ideas what it could be? An easy fix perhaps..?

Or any suggestions at all?