Starter motor questions - rebuild

[Jezza_hr]

Hey guys.

I've had a few starter issues I've been trying to resolve today and after some troubleshooting I'm trying to narrow down if it's the copper connectors or something else.

I can get the magnet to move out the gear if I connect it to the opposing side of the motor (the side that usually has a rubber seal over it), but the motor itself doesn't turn. I have no issues moving the cog by hand if I pop it out.

Looking under the covers, one of the copper connectors looks slightly galvanised, but I wouldn't have expected this to make a difference if the magnet slides the cog out? Am I missing something