my iphone 4s won't connect to itunes

i was using my iphone 4s when the screen went yellow then turned off (it also happened the day before but went black then turned off) and i could not get it to go back on again. after a day, i went back to it and it had came up with the "connect to itunes" restored screen which i thought was great. however, when i plug in the usb to my laptop, it makes the connecting noise but does not actually connect to itunes in any way. i have tried many different usb's to see if that is the problem but i just can't get it to work. anyone have any advice?