First off, I'd recommend asking about  repair details from several techs. Things  like voltage caps are standard pieces that  can still be located. Likewise with key  contacts, etc. If the main CPU goes, you're  simply screwed and far from home, as  companies can only keep those molds for so  long before they move on to the next model,  leaving you with no options. That's one of  the more annoying aspects of the electronics  biz, but a reality all the same.
  Second, when/if you get them back in usable  shape, leave them at home, period.  Instruments of that age don't do "road" well
 and will behave better if left in one place.  Sampling them is highly recommended.
  I'd suggest these possible repair sources:
 *e-mail Analogics at flattop@suite224.net
 *www.analogsynths.com
 *Caruso music at caruso.net
 *roguemusic.com
 *Used Gear By Mail at ugbm.com
  One or more of these outlets is almost  certain to help you get a handle on  resucitating your Korgs. Hope that helps.