I bought a used IDX pro that is in excellent condition but when it got to me all the nickels were hitting in the foil range. I called someone and they told me what to try and adjust to get the nickel to read correctly. I made some adjustments to the vr3 and the vr5 and now it seems to be working fine. Can someone tell me what the blue boxes with vr3, 4, and 5 do excatly. I found this picture on another post hopefully the person dont mind me using it. Thanks.