Got the old etrex out the other day, and it wouldn't start. New batteries didn't help either. So I figured what the heck it's only about 25 or 30 years old I got lots of use out of it, I'll get something else. So I threw it on the work bench, and forgot about it. Fast forward, I uncovered it and wondered if something was fixable inside so I tore it apart. Lots of glue holding the two halves together. I found where the battery contacts were on the mother board were a little corroded, so I sanded them, also sanded the springs that make contact from the battery half, and it came back to life. Still had the waypoints, routes, I'm happy.