Hello, upon taking the lever mechanism apart I can see why it doesn't work. The lever turns a small nut shaped hexagon which in turn moves a tiny lever within the housing. The hexagon has worn down so it no longer grips the inside of the tiny lever. It rotates without moving the tiny lever that it is supposed to move. I'm not able to take the mechanism apart any further than what is shown in my photographs.
My windows were made by Alside. They were installed in 1995.
Can I get the needed replacement parts? Thank you.