Hand-held Nokta Macro (Pulse Dive) detector not working

[OBXmetalDet]

Last week, at the Outer Banks, I tested this before going into the water and it worked. Sometime after coming out of the water, when I turn it on and wave it over metal it doesn't beep. What could be causing this and how can this be fixed?

 

[Gare]

Could you have reprogrammed it ?

 

[OBXmetalDet]

Could you have reprogrammed it ?

I guess that depends on what you mean by reprogramming. Is there a way to do a factor reset?