Electric keyboards range from simple, inexpensive learning tools for music students to multi-thousand-dollar instruments for professionals on tour. But if the keyboard's AC power cord doesn't provide current, you won't be able to use it. The lack of power could indicate a major problem with the keyboard, but it also could be a minor problem easily fixed with some basic troubleshooting.
Check the AC adapter connection on the back of the keyboard and secure any loose connections. Most AC adapter cables detach from the keyboard as well as from the wall outlet, so check the connection at both ends.
Plug the AC adapter into a different outlet to check for a "dead" outlet. If you have the keyboard plugged into a surge protector, move the AC adapter to a different slot on the power strip or bypass the power strip by plugging the adapter directly into an AC outlet.
Purchase a universal power supply and attach it to the keyboard and an electrical source. If the keyboard powers on, use the store-bought AC adapter instead of the factory adapter. If there is still no power, the keyboard likely needs to be serviced.