infant mortality n.
It is common lore among hackers (and in the electronics
industry at large; this term is possibly techspeak by now) that
the chances of sudden hardware failure drop off exponentially
with a machine's time since first use (that is, until the
relatively distant time at which enough mechanical wear in I/O
devices and thermal-cycling stress in components has accumulated
for the machine to start going senile). Up to half of all chip
and wire failures happen within a new system's first few weeks;
such failures are often referred to as `infant mortality'
problems (or, occasionally, as `sudden infant death syndrome').
See bathtub curve, burn-in period.