Not sure why you'd think that; flaky means flaky. Neither flickering nor pulsating is therefore precluded.
Does the behavior change as you move or flex the lid, for example? If so, that is a strong indication of a connector-related problem. Intermittent cable connections are very common in these older 'books (this affliction was notoriously widespread in the 1xx series, but affects other models to one degree or another as well).