Why does my iphone keep restarting itself?

Hey I have the same problem of my iPhone 3GS restarting every 2/3 minutes. I've read the solutions posted here but the problem I have is that I can't restore the phone. As soon as the phone restarts, I cancel the automatic sync, select restore and select back up files. But everytime I try, the phone restarts halfway through the backup process and iTunes tells me the phone is disconnected and backup can't be completed.

Any idea of what I can do since restore doesn't seem to be working for me.

Hello, my brother had this same problem of the iPhone 3gs restarting cuz of the ios5. I tired enabling the 3G n dat but it only lasted for a few days them start rebooting itself again.... Try this method not sure how long it will last for but. Good so far.

General/reset.....Erase all data and settings.

On the iphone......Set up as a brand new iPhone.

Then log in with your apple i.d on your phone.

Once done, restore it from the pc and then sync ur backup with your apple I.d(if u hav 1) if u don't have back up saved it don't matter.

HOPE THIS HELPS YOU.

Because i know how frustrating it's been

Was your reboot problem solved? I have 3g iphone doind same but it has OS 4.3.5 Dd your problem stay solved???

What about a reboot problem in my 3G A1303A, OS 4.3.5, it was dropped in some water, but taken out right away and cleaned, did not blow the sensor, will not stay running long enough to restore or upgrade to 5.0, any ideas if you know what needs replacing if water did get into it.. Thanks

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!

my iphone4 new buy, restart itself randomly, idk why, i try to restore it in itunes, but i keep my setting. then 4 days going well, but then day 5, it keep restart itself again, i try to applestore in my country but it takes process longtime, they give option to restore or change to new one but takes 3 months! my last try is, i will reset phone to the original with no setting keep, then see what happen, if it still restart itself.. i cant take 3 months to wait. im so disapointed :/

and there's no guarrante they will have spare new phone to change with 3 months wait.

jesus...