Why does this solder connection only connect for a short while?
Hi, I recently (as of last night) built a hot wire foam cutter and it has a small problem. Every time I plug it in, the wall wart produces a high pitched whine and the wire does not heat up. I have to unsolder the wire and re-solder it every time to make it work. Is there a way to resolve this problem? The nicrome wire is attached to a loop of copper wire and the end of that copper wire is soldered to my power source.