I have power supply for a vintage Timex Sinclair. The unit was sealed but the cable felt loose so I pried it open to inspect the connections. There was a knot on the other side so it was just the cable slipping between that and the outside and not on any solder joints themselves. But I also found the transformer to have a lot of rust on it.
Can this be cleaned off with vinegar and a wire brush or will I need to replace the whole thing?