iphone 4 turns off and on itself

Probably a hardware problem,... use your 1 year warranty.

have you tried doing a hard reset by pushing the home button and the screen on off switch at the same time till it reboots

I have been experiencing this problem on 4S for the last two days. I bought the phone BRAND NEW last week, so I'm pretty bummed. I figured I would backup everything on my mac before I did anything else, but every time I clicked backup, my phone would restart and the backup wouldn't complete.

AT&T tech support weren't helpful and turned me over to Apple support. They suggested I erase all data on my phone and start the phone out as "new", as maybe it was just a bad app I recently downloaded/purchased. Luckily for me, I had backed everything up a day before all this crap started happening. So I restarted everything last night, started to bring back some of my apps, but not all of them! One at a time, to really see if it was a bad app. Just my luck though, I haven't finished getting my phone back to where it was two days ago, and my phone just shut down and restarted on its own. Reboot/restart did not work. FAIL.

I have to take it to an Apple store and most likely have it replaced. Hopefully you all have good insurance and/or your phone is under warranty!

i had that same problem! but after 15 minutes of continues on and off, it start again as normal. do i need do bring my phone to the store where i bought it for repair?

I have the same problem. I just got my iPhone 4 as a present a couple of weeks ago and it started to turn on and off by itself. I wanted to take it to the apple store, but I'm not sure if it has a warranty. is there any way i could fix this myself?

Yes