If you are not happy doing that kind of job (ie tracking down what is wrong and replacing it, Id suggest a trip / phone call to your local music store and ask there advice regarding who to contact locally. Failing that I imagine Boss US have a list of dealers / service centers on there website.
My instructors page and www.studiotrax.net for all things recording.
my toons Brought to you by Dr BadGAS
my toons Brought to you by Dr BadGAS