Jostling it with things like air, suction, Q-Tips, toothpicks, ballpoint pen inserts works for some, but not for me. Tugging on it with a bent-tipped safety pin while watching through a magnifying glass works, but only until the next time I unplug the headphones, and so is too impractical. The one plaguing my Late 2006 MacBook is the tip contact.
Staring into the glowing red Cylon eye, they are: 2 'sleeve' contacts (nearest you), one at 9 o'clock and one at 3 o'clock (positions on an imaginary 12-hour analog clock dial) 1 'ring' contact (farther in) at 12 o'clock and 1 'tip' contact (all the way in) also at 3 o'clock. The Apple 3.5mm headphone jack may have multiple different failure modes, since it contains 4 equally flimsy electrical contacts.
