iphone wont turn on after reset,start in loop!?!?!

i just swaped my blackberry with a friend for an iphone, when i swaped it i knewn that i had to get the home button fixed which is'nt a prob, as im going to get it done on the weekend.so i get the iphone back home and reset and erase all content, because i didnt want any of there music pics ect on the iphone.but for some reason the iphone will not turn its self back on it will just keep showing me the apple icon and a round circle keep going around, it will stop nd then just start again, im really stuck as i am new to iphones and have no idea what im doing,the friend did say the iphone was jailbroken,which i dont want either,is this why the iphone has broke?

please help!!!