In response to a question from a client of mine, here’s a short video on how to tighten up loose tuning pins. It should work on any make of harp that has pins that run all the way through the neck, as opposed to the zither-type (or Autoharp type) pins that are screwed into the string side and tuned from the string side. As I explain in the video, tuning pins tend to work loose, especially when a string is replaced. All that is usually needed is to push them a little deeper into the hole in the neck. The hole is tapered to fit the shape of the pin, so the more you push them, the tighter they will feel and the better they will hold.
I’ve heard of people who try to accomplish this by whacking on the back end of the pins with a hammer or mallet. While this should theoretically work, in practice it rarely seems to, and there’s the danger of that hammer going where you don’t want it to. Try my approach and see how it works for you.