PolyFuses/resettable fuses (http://en.wikipedia.org/wiki/Resettable_fuse http://en.wikipedia.org/wiki/Resettable_fuse) are often at the root of that sort of beh

PolyFuses/resettable fuses (http://en.wikipedia.org/wiki/Resettable_fuse http://en.wikipedia.org/wiki/Resettable_fuse) are often at the root of that sort of behaviour.