Maybe, just maybe, call the manufacturer first.
If it is within warranty, then, you know what to do.
If not, then it is either a amp replacement or a driver replacement. I believe both would cost you around half of the sub if the manufacturer have spare parts.
There are indeed local repairs that could found... but surely it is your job to find where are they and ask for the price. If it is a simple burnt conponent like capacitors, it should be easy to fix and I image it would cost you maybe $50-$100? If it is a chip being burnt, it could be more expensive or sometimes not fixable. (this is rare because most sub does not have tons of logic chips onboard, nor are they easy to get burnt)