My computer is not turning on.

[Hazzard]

My computer isn't turning on, I think it's something to do with the power.
I've changed the power cable, plugged it into a different socket and turned the power off and on at he wall and at the computer.

When it is plugged in the internal light is on, so it is recieving some power, but it won't start up properly, but sometimes the fans will spin for a split second and then stop.

Edit: Fixed it, I replaced the Power Unit and some cables and it's fixed.