Prizm IV will not work in any kind of sand

I have had a Prizm IV for almost a year now and have an issue that that maybe one of you might be able to help me with.  My machine will not in anyway go through any kind of sand in discrimination mode.  regardles of settings..  I switch into all metal and "might" get an inch or two but that is it.  It is so bad that I can go to any play ground and it could be sand or pea gravel and with just a light skiff of sand or rock over a placed coin and the detector does not see it.  The machine works well in grass as long as it is dirt that is the base but no go if there is only a slight layer of dirt over a base of sand.  I will only find coins in the dirt layer.  I am in Alaska and only coin shoot and we do have mineralized ground here but this is getting to be a real bummer.

You can adjust your GB to your area...  I have one and do not have that issue at all,
and I take mine to our local swimming areas, which is obviously sand...  Mostly white
sand and not mineralized at all...  But I can get the same depth in this type sand as I
would get in an air test...  So maybe all the sand in your area is highly mineralized....

I would suggest putting your machine in all metal, then bobbing your coil up and down
from about 12" to 1"...  Does the threshold sound increase or go silent??  I assume that
if you are over your sand, that it must go completely silent... 

You are welcome to e-mail me and I will go through the GB procedure or give me a call....

jeffrey.beecham@volvo.com           731/967-8458       

Thanks, Jeff