Hell to all,

I recently bought a Marshall DSL 100 hr head and after a few weeks there is no sound if I choose the 100W setting, it will work on the 50 w setting. A few days back I noticed that if I used the FX loop the volume drops. I asked my dealer Guitar center in San Diego CA US, and they told me I need to contact Marshall US first for the warranty, even though the warrantly specifically says to return to dealer. Please help, the amp is not cheap and I have important gigs coming up.

Thank you.