HP Tower (2000 Media Edition)

Question

I don't know the exact model (not @ home). Powered down yesterday before I left for work. Ten hours later, pushed the "tower" button and NOTHING happened. I am miserable w/o my comp at home. Checked all the connections to no avail. I am computer illiterate. Can anyone suggest something that I can try? It was FINE yesterday morning and then BOOM, it is dead.