Sounds like the KW500 has a short and fairly large fuses?
Sometimes you can see or smell what is fried by popping the cover off (after ac power disconnected and caps are discharged!) and giving everything a good look see. Other thing, if it is tripping a GFCI breaker you might just be looking for a slight short to ground, sometimes you can get resistance to ground back up to snuff by just blowing clean with an instrument air bottle (radio shack) and wiping away obvious dust.
Sometimes you can see or smell what is fried by popping the cover off (after ac power disconnected and caps are discharged!) and giving everything a good look see. Other thing, if it is tripping a GFCI breaker you might just be looking for a slight short to ground, sometimes you can get resistance to ground back up to snuff by just blowing clean with an instrument air bottle (radio shack) and wiping away obvious dust.