Greg, the original batteries are expected to last 12-18 months. When mine failed, I had the same issue. This is what I discovered. Remove the batteries, then cover the solar cell with a piece of black paper, wait about a minute, put the batteries in then uncover the solar cell.
Now it just flickers about every 15 (or so) seconds.
That is normal, transmitting data to the console every 16s.
There is a little hole next to the led where you can also force a reset with a paper clip.
I replaced mine with Duracell NIMH and been running on that for almost 12months now.