Only the UK and Ireland have these godforsaken, ugly, outdated, oversized powerplugs with fuses in them.
The rest of the world enjoys more pleasant looking plugs, but all without fuses!
Check that the powercord is properly plugged into the back of the computer.
Try a different cord and a different outlet.
If you are technical, there is also a fuse inside the Powersupply (but this is strictly for experts only! Danger, High Voltage inside!).