Going through the late answer review queue, I came across this answer. While it should normally be helpful ('root' and 'toor' should be the default username and password from what I recall), in this case, the question specifically states that 'root' and 'toor' did not work.

Should I flag it "not an answer"? It does "attempt to answer the question". Is there some other flag I should use?

Or should I just sacrifice 1 rep for the greater good and down vote it, without leaving a flag?