Weston Master 6 stuck on problem

I have a Weston Master 6 model 560 that seems to be stuck on. Just noticed this a day or so ago - usually you have to push the little button on the side to make a reading and when released the button pops out and the meter needle stays put. Now it is just 'on', and nothing happens when I push the botton. The button has a screwdriver slot, and using a small screwdriver I have turned both clockwise and other way and it just free-wheels and doesn't change a thing. The button is "in" and won't pop out, but it doesn't seem to be in a bind because it does turn easily and seems to have a little side-to-side play in it...
I don't have any literature on it - lost manual long ago. I believe the little slotted button is supposed to be adjustable for constant on or the off position, but I'm not sure- and even if it is, turning it doesn't do anything. Please - can anyone tell me how to fix this?

wcwiseman@highstream.net

wcwiseman,
the switch is just a pressure contact, not electrical. If you can get the housing seperated you will probably be able to see the problem & correct it.
Unless it bothers you it really doesn't need to be fixed. Since the cell is silicon & requires no battery It's really not hurting anything.
Thinking about it, having the needle locked down may protect the movement from mechanical shock from being bumped around.