Apple Power Macintosh 7100/80AV - Manual (Page 57)

Take Apart Power Supply - 5
2 If there is a power
supply strap installed on
the unit, squeeze on the
two ends of the strap and
push it through the
metal opening to remove
it.
Note
: The power supply
strap is part of the
shipping packaging for
some power supplies.
When replacing the
power supply you
should replace the strap
if present.