quick history: I buy a new Forerunner 201 in Oct. It works flawlessly (more or less) until about 3 weeks ago. It suddenly won’t hold a signal…when it does it goes crazy. 6 mile runs show as 341 or something equally as ridiculous. Mostly though it stays blank. I freak out and buy a new one. It comes in yesterday. I wear it for the first time this morning and it does the very same thing. Stayed blank mostly but it came alive here and there and registered a mile about every 30 feet. If it matters, I live in SW Michigan. What is my problem with these stupid things?
Never had any probs when I run in that area. My broke once and Garmin sent me a new one though.
Couple of thoughts - first you can do a hard reset/master reset using the procedures documented here:
http://home.socal.rr.com/diverhank/ForeRunner201.htm#_Toc98428399
And, you might want to be sure you are running the latest software revision in the unit itself (go to the garmin.com site to download the latest version (which is 3.50) and update your unit.
The one time (in about 300 runs and rides so far) that mine went totally wacky like yours and started rattling off miles every few seconds, just a regular stop and reset of the current run seemed to fix it.
About every 12 runs or so I get a lap displaying as something like 3401km completed in 5 seconds. Pretty impressive hey?
Otherwise I love the thing.