So I went to get this baby ready for the boomboxin' season coming up soon. I picked up some rechargeable energizer D batteries, and suddenly learned that my box won't power up with batteries alone. :'-( So I noticed a minor amount of corrosion on the contacts and smoothed them out lightly with the dremel.... still no power Any ideas why this would be happening? This box is in excellent condition otherwise and works perfectly plugged into the wall. I appreciate your time fellas