I agree with mtnwalker.
I once bought a cheap(~$60) scope. It had a loose locking ring rattling around inside. Sometimes it would block the view through the scope. If I rattled it around sometimes I could see through alright (except for the oil/greese smudges it left on the inside of the glass. I took it apart, re-installed the lock ring, cleaned the inside of the glass, and re-assembled. It works fine still as a cheap scope on my 17hmr.
I generally wouldn't recommend taking apart scopes or binoculars and would send it in if covered by warranty.