Make sure the computer is plugged into an outlet that is on.
Make sure the power strip is turned on.
Is the power cord securely in the computer?
Is there a power switch on the back of the computer? (usually near the power cord)
Is the computer set to 110V/115V? On the back of the computer next to the power cord may be a switch that can be set from 110V/115V to 220V/230V. Make sure it is set to 110V or 115V.