My Kenmore side by side refrig/freezer, with an ice maker/water dispenser is about 9 years old. It works fine is every aspect, except, that water collects in the bottom of the freezer and freezes almost daily. It appears to be dripping from the coil mechanism on the inside, back of the unit. There is no drain plug in the bottom. It gathers up to 1/4" of ice in a 8" x 10" area. I defrosted the freezer, and took apart everything I could inside to see if a visible leaking area was prevalent, and it wasn't. Any ideas?