[Buzz]

It sounds like an alternator issue to me. If you can swap it out for a good one to see if all becomes well again that would be very telling. If you have a good alternator and still no electrical power, then I would look at the wiring in the starter circuit, in particular the fusible link if you have one.
Here is the relevant circuit from my Unique. Bear in mind I am running a Chevy engine () so your circuit may be slightly different. Wire numbers and colors correspond to the wires in the harness and the manual that came with it.