Finding the Shorted Component on a Printed Circuit Board

Once in a while, you find yourself staring at a printed circuit board with a shorted power rail.  It could be any of the components, capacitors, diodes, ICs.  Sometimes, you have a hunch which component might be bad and remove that component to see if the short goes away.  But you might take off one component after another, still could not located the bad component.  

One way to quickly identify the faulty component is to apply current to the shorted rail and look for the hot part.    You may have to apply a few amps of current, but not too much current to damage the traces.  Sometimes you can actually see a component starting to smoke; other times, you have to feel the heat.  If you have a thermal imager, you can easily see the hot spot.