Unless the router is special for some reason, it's usually better to just buy a new router than try to find parts for any router that is no longer in production. The new router will have many improvements over the older one, and in many cases won't cost that much more than having the old one repaired, if parts are even available to repair it. Soft start, plunge, and multi base capability make new routers much better than routers of only 20 years ago. One of my oldest routers is now cordless (I cut it off) and doing its new job as a door stop. It was a great router when it was new, but it is very obsolete when compared to today's routers.
Charley