Hi, yesterday for the first time, my 2500 had periods of "non-imaging" moments. I have had this unit for a couple of months now and this is the first-time I have encountered such a problem. I would get a good signal, then proceed to press the "treasure imaging (pinpoint)" button and there would be nothing on the screen! The unit even would not identify the conductivity of the metal. The sound would be there, but that's all. Any suggestions? This was an on again and off again situation. Thanks........Martin.