Won't power up. Just a very low volume high pitched sound.

I have this Epson Artisan 1430 printer that I used to really like. While I was reloading the cartridges, the LED's all went dark and the printer began emitting a high pitched sound every 2.5 seconds or so. It is a very low volume sound and the only way to stop it is to unplug the thing. The printer does not respond to the press of any of its five buttons. Anyone have any idea what this could be?