If your gadget isn't working, your first instinct is to give it a good whack! That worked a lot better in the days of rust and shorted out wires than it does with your computerized electronics. The movies still do it, all the time! The technique is called Percussive Maintenance, or my circle referred to it as Impact Technology (we did a lot of this at radio stations). This supercut was edited by Duncan Robson with music by Joel Robson. -via Colossal
Even today, with our computerized electronics, we may be able to overcome marginal performance of a component with percussive maintenance. The vibrations that are induced by percussion may create random fluctuations in the signal between components ('noise') that may make the actual signal more detectable. This is a phenomenon called Stochastic Resonance.