My iPhone 3Gs keeps going to factory settings when turned on?

It goes back to factory settings & ask to connect to iTunes. But when I wait a while it goes back to normal but get no phone signal? & the screen has been replaced on the phone.

It's busted who ever replaced your screen may have did something wrong. Take it to apple to get diagnostic test

  • What settings will it change if I press reset all settings on my iPhone? Also, will this help speed up my iPhone because that's what I've heard. Because my iPhone has been so slow lately and taking like 3-5 minutes to send 1 text. If you know of any other ways that could help speed that up please also let me know that.
  • My iPhone turned off by itself and turned back on while using a app? When I was on YouTube my phone just shutted off by itself then turned on. Is there something wrong with the phone. Also when I click my home button one time the phone sometimes wouldnt come on till the second click. What can I do?
  • My iphone 4 froze, screen turned green and turned off? I was playing a game i regularly play when it froze. I let it sit there for a couple minutes, I pressed the home button and the screen turned green, It was green for a minute. It shut off and won't turn on. I plugged it into the charger 20 mins ago and still no response. Also, my power button broke a whille ago. What can i do? Keep it plugged in until it turns on or should i unplug it for a couple days?
  • My iphone 3gs won't restore to factory settings? I bought an iphone 3gs for $50 from my friend, it worked fine except i had to restore it. It automatically updated the IOS but when it finishes restoring it gives me a message that says something like: "itunes could not restore your device due to an unknown error(-0)." any idea on how i can fix it? Or does this mean my iphone is obsolete and will no longer work?