Reebok heart rate monitor won't work after new battery.

I contacted SportBeat Inc. with the same problems you reported. I sent back the old watch with a $20 check to have them replace the "module". (This is what they told me over the phone to do.) They sent back a brand new watch in less than a week, and returned my check! (Maybe I was still under warranty?) Anyway, their phone number and address are on the back of the manual. They were very responsive to phone calls and emails. Good luck!
Sport Beat Inc.
45 Jefryn Blvd.
Deer Park, NY 11729
1-888-760-3059