When I bought my eTrex Vista, 3 years ago I noticed while riding my bike the unit powered off every ride. I went to the shop I change the unit but the second unit had the same behaviour. Again changed the the unit. Unit 3 had the same problem: it powers off. I wrote to Garmin and received new pads and contacts. It didn't work. Today the units continues ... with the same problem, on the bike or just on the dashboard. It powers off several times.
I THINK THERE IS NO SOLUTION.
Nakuru, October 2007