Hi,

I recently purchased a new Marshall ST20c combo amp. I absolutely love the amp. However, I purchased a Keeley reverb pedal (new) and decided to try it through the FX loop of the amp. I got no sound at all. Then I tried it through the front end of the amp and it works perfectly. Would I need to get this fixed under warranty or is there something I'm not doing correctly. I plugged the send from the amp to the input of the pedal and the return of the amp to the pedal's output. Please advise A.S.A.P. 
regards

Stephen Hubbard