Won't boot up. the screen will show:analog inputenergy saving modemove mouse, or press any

Question

the screen will show:analog inputenergy saving modemove mouse, or press any keytried replace key board and mouse , but the new ones don't work either. it just seems like it try 's to boot up , but after 2 seconds it goes into sleep mode. it is probably something simple, i have tried every thing i can think of,and no good.please ....any ideas?thx,haydon