Why does my iphone 4s keep turning itself off and on?

My Iphone 4s(Jaill broken) wasn't showing the home screen wall paper so i thought it was one of the Cydia tweaks so i started deleting some of them made my iphone stuck, so i desided to turn it off and when i did it keeps turning it self on and off on and off… And i won't connect with my Computer and i'm not in America atm so there's no Apple store around can some one please help me?

Don't jailbreak, it will mess up your phone. Just restart your phone by holding the power button and home button… Should work. If not, call apple.