when my watch is flat on my wrist it works but as soon as i inclined 180 degrees on the left side the watch  stops working. I had a similar problem back in June 2013 I sent the watch it was fixed but it happens again. Like I said previously I never dropped or bang the watch . I don't know the serial number of it but here the details of my purchase with Groupon code: 0010020YEOSecurity Code: 2FA17DCB46 Thank you for your help 
Regards