Jim, I had the same problem and took it back and got a new one. On the new one I went back to my area of fishing and had the same problem... I was without words it worked for a bit then got "O" on the display again. This took place two years ago and I have not tried this product again. I wanted to use this on my canada trips but with the problems I went with another product. I hope you can get some feedback on this as I tried with no luck. I know alot of fishermen that use it and has no problems as we did... Maybe some bad luck... Hang in there and hope you have a great year of fishing...
"May Your Fishing Dreams Come True"
Fish Detective