One of our volunteers had a suitcase with a handle that would not fold down.
The handle mechanism was removed by unzipping the inner lining and undoing six screws.
This revealed a dent in the handle mechanism that was causing the problem.
The dent was pressed out with a pry bar from the inside while held in a vice, followed by some gentle taps with the hammer to knock out the reverse dents from prying.
Once the dents were straightened out, the suitcase was reassembled and the handle worked correctly.