Today I was trying to use my Edge 830 for some CX prerides. It would boot up just as usual. I would select my activity, press start and within 1 to 2 seconds my 830 would reboot. I tried to repeat the process and would try different activities only to have it do the same thing. I used this same 830 yesterday for a MTB ride and it worked fine. The only oddity would be that it would keep "finding" my SRAM derailleur.