Keyboard problem

Hey guys! I need some help.
My keyboard(Keystation 61es) don’t give sound to my program(Cubase Es 5). Really don’t make any sense, my keyboard was working OK, and no problems!
So, what should I do?

Do you want to record the sound generated by the internal sound module of the keyboard (if it exists)?
Or do you want to record MIDI?

Are you still able to locate it in your devices list? USB ports can be finicky as well. Try unplugging the device from your computer and plugging it back in (same port or a new one).