I was checking a VHF boat radio for power polarity, using my car
battery. Both polarities immediately blew the 10A in-line fuse. I had
the radio sitting on the car and I realized that the heat sink was
touching the sheet metal. The radio had worked before, so I assumed
that it was the heat sink contact which had caused the fuse blows. The
radio now shows a dead short between the input power leads.

Questions:
- could the heat sink contact damage circuitry? I would _think_ that if
the heat sink was connected to anything it would be the power "neutral",
directly, and not through any circuitry. Is it possible that it was
connected through active circuitry?

- if the heat sink contact did cause it, what is the likely extent of
the damage? I.e., would it be worth fixing or is it likely trash? (It
is a Standard Horizon radio - maybe $100 on eBay.)

Thanks,
Bob

BTW - is there a better newsgroup to ask?