Why my phone won't turn

after I have ,press the power button,and then I press recovery ,then I press reboot and reset phone ram ,,then I see something came on the screen,asking , would you reinstall your phone ram by your self ?I did not wait a second to think so I said yes ,after a while the screen when off ,then I press the power button and I see Samsung and then it switch off back it keep on doing the same thing .can some one out there help me please ,its the only phone I have