Okay try a couple of these things:
1. Remove the disc and power it on with nothing inserted.
2. If you're using an extension cord or power strip, plug the cord directly into the wall outlet.
3. Clean the laser lens, controller and memory card connectors, and AC adapter connector. Carefully.
4. Plug the cord into a different wall outlet.
5. Remove all controllers and memory cards and see if the system powers on then.