One thing I would check too: with a power switch THAT blown up, I would verify that the power transformer is still good, and that this unit was not the subject of a lightening strike. I hate to mention that thought, but the usual and typical power switch failure simply does not blow up and (apparently) catch fire in the manner that this one appears to have done.
Dave
The power switch has been bypassed at some point, and the previous owner did have it up and running. I have spare iron laying around here also if need be.