First check the computerís power cord to make sure it is completely plugged into the wall socket. If you are using an extension lead, make sure it is completely plugged into the wall socket and that the power switch on the extension lead is turned on.


Some extension leads also have a built in circuit breaker which usually looks like a black or red button near the power switch. Press the button to reset it and see if that solves the problem.


If none of those work, you should think about getting an expert to take a look at it.