hey, i'm fixing a vintage bike (80's bianchi) and I wanted to move up a little bit the stem. Unscrewed the top bolt and wasn't able to move it up or down. So i hit the stem from below with a hammer a couple of times, I couldn't move it too much if any at all but I think I did move the top compressor (i don't know how it is called) a little bit upwards (I think there is a space where didn't use to). The point is that now if I put back the top bolt on the stem I can't tighten it, it just moves freely (the bolt). And still can't move the stem up, down or free from the fork.
Is this a seized stem? If it is how do i fix it? I found that to fix a seized quill stem you screw the top bolt and hit it with a hammer, but as I can't screw the bolt I don't know if it would help.
Please answer shortly, I've been fixing the bike for months and can't see the moment to ride it.
I also need to unscrew the bolt under the handle bars to change the angle, but it seems seized af. Please any help is welcome.