Define "blow up." I've never seen a KRC killed by an Ethernet connection. I suppose it is possible, if the dropped switch put enough excess voltage onto the Ethernet cable, but that seems like a highly unlikely failure mode.
Swaptronics on KRC1s isn't hard, it's mainly a matter of picking the correct components to swap. I once had to swap motherboards on a KRC1 with no tools aside from my Swiss Army knife... while keeping the original processor, RAM, and ISA cards. Took about two hours. While I've found the components to be quite robust, take precautions against static discharge anyway -- it's cheaper than new parts.
If you have another working controller, it's easy to swap entire PC racks -- four or five cables, and lift the rack off its hinge pins. Oh, and swap hard drives, of course.
If you want to swap individual cards, well... depends on exactly how your KRC "blew up."