Compaq Armada 7400 Reference Manual page 12

Plug the power cord into the AC Adapter.
Plug the AC Adapter cable into the power connector on the
back of the computer.
Plug the other end of the power card into an electrical outlet.
In Japan, you must first plug the power cord into the
3-to-2-prong plug adapter included with the computer. Ensure that
the ground wire is connected to a safe earth ground, then plug the
3-to-2-prong plug adapter into the electrical outlet.
!