If I answer "trying to find what is not working and fix it" I might be describing a plumber, but somehow I think that is a philosopher, no matter what he calls himself.
I think whenever we set out a problem, or guess there might one, or try to fix one, we are being philosophers. By a problem, of course, I mean some configuration of reality around us that is improvable.
A "true" or, well, "full" philosopher would be someone able and keen to address every aspect of his life as a potentially solvable problem, so that eventually he would reach an optimal state with a set of fixed rules to optimally develop, learn and follow the best strategies for him in every moment.
I sometimes wonder whether there is or not a fundamental distinction between technical and moral problems, but I think that, even if we are forced to make that distinction whenever we deal with other people, for moral more or less implies "the consequences of our acts for other people", it is not a fundamental one. Other people are just part of our reality, and the way we deal with them is, ultimately, a technical problem.