All Rang™ loopers we've encountered could be repaired except the one that spent 3 weeks under water in New Orleans after hurricane Katrina. Since deciding to sell Boomerang, we have been directing customers to contact British Audio for repairs. They have all of our schematics and seem to be a competent outfit. Before sending your pedal off, please contact them. 

British Audio 
5343 Charlotte Ave., Suite B 
Nashville, TN 37209 

If you are going to send your pedal, include a note with:
1) your name
2) phone number
3) complete address where you want your unit returned
4) a description of the problem - The more detail the better.

In Europe, these guys MAY be able to help you:
BassLab Electric
Borups Alle 3
DK 2200N Copenhagen
tel. 45-38-88-2882