When can a tenant withhold rent?

If a tenant were to enter into a month to month lease (presumably written) with a landlord for an apartment with predetermined features (ex. appliances) but then complain for the lack of screens on the windows and alleged pealing of paint in the bathroom can they justifiably withhold rent? Letters were exchanged. The landlord explained that the apartment was rented without screens so he doesn't have to supply them and the paint was "inspected" by the apartment's janitor who concluded it was "chipped in one or two spots" so it didn't need to be replaced.