In my in-laws' house, there is a receptacle in the basement that would not work. I plugged in my tester and it said there was an open neutral. I opened it up and there was a loose neutral wire. After connecting it, there is no response at all from the tester. I replaced the receptacle with the same result. I've replaced over 100 of these things, so I know how to do it right.
This receptacle is on the same circuit as the outside one (which does not work) and a GFCI receptacle in the basement bathroom (which works). Any ideas?