It's really very simple. The fault in Buerste's refrigerator that
mysteriously disappeared when he took it apart (see "Take apart - put
together syndrome" thread) has tunneled into your refrigerator. It's
one of those quantum mechanics things that physicists can write
equations about, but nobody really understands. The best that you can
hope for is that your fault has a propensity for tunneling and that it
will do so & go somewhere else. There is some evidence that taking
apart & putting back together can provoke tunneling.

Good luck,
Bob