Can anyone help me figure out how to fix this watch? I had seen a video that said it was likely that Center screw being loose so it wouldn't wind, but even after tightening that it won't start ticking. Bought some simple tools and I'm willing to mess with it (I believe it was a cheap watch) I just have no clue what to do.
The modern version, NH3x (the last digit varies based on features) can be picked up aftermarket for about $50. The NH (which Seiko also calls 4rxx) is a drop in replacement for the 7s26, but includes handwinding and hacking. These ones from Crystal Times (no affiliation) are also regulated so they are more accurate than what comes from the factory.
You will also need to purchase a new crown stem, and you'll probably want a few tools as well.
A seiko service has to go to an authorized seiko service center to get parts these days, but even a basic service can run over $100