I started having issues with the phone any time I will go on the Internet my phone will shut down having 70%
of battery .when I was able to turn it back on it only had 6% of battery. but at least it will turn back on today its not working
it turns on and it only gets to the 4g start up page and it turns back off HELP PLEASE
I'm sorry that's happening to your phone. Usually with this issue we need to reset the phone with the keys. Unfortunately it's a full factory reset, so any information not on your SD card is set back to factory conditions. Your contacts should be backed up to your Gmail account.
Just to clarify; Do you have the Original Galaxy S or the S2?
Here's a good step-by-step video on how to complete the steps. Let me know if you have any issues getting it done.
I had exact same problem, went to sprint store, they said my battery was bad, they replaced it and did a factory reset, and now my phone works awesome, battery lasts all day no problem and everything works fast and great.