E31 is a programming error code. Most of the time this comes from using non-alkaline batteries or from letting a battery die in the unit. "lob" means low battery condition. In these rangefinders "lob" will show up with a new non-alkaline battery installed. Non-alkaline batteries just don't generate enough current for the laser to operate properly. Reprogramming costs about 20 bucks, if it needs an alignment (won't hit a flag or target at 200+ yards >50 bucks<) Oily looking spots in the display are from not using the eyepiece cap and direct sunlight damages the LCD. (15bucks) The address for repair is:
Bushnell Repair Center 8500 Marshall Drive Lenexa, KS 66214
800.423.3537 Send a problem statement, your phone number, and $10 for return shipping.