A power surge zapped my JVC MX-D661T com...

Open it up and check for internal fuses, if any in there, test with a wire, bulb and battery. The values (voltage and amperage) will be on the fuses or next to the fuse holders. Also look for any obvious burnt components like diodes( small bleck tripods) and capacitors(coloured "tubes" with a wire at each end) and resisters(like capacitors but with coloured stripes on). Obviously it will be cost dependent.
And most important UNPLUG BEFORE OPENING and be cautious as capacitors may be small but they can hold a very high voltage for a long time.