iPhone boots.. Then dies!!!

Did you leave it on mains charge for a couple hours? If so, you likely have a battery/charging problem.

My friend had that problem too, he took his phone to a shop and they change the battery and it stopped doing that most likely its your battery.But i would keep finding out more solutions since the problem could be different.

you should post this offering on a ton of problem boards because it amazes me how many people struggle and struggle with older phones when you can get new or refurbished ones for such a little amount 😉 so what about the contract...if you aren't jailbreaking your iPhone, you need an AT&T contract anyhow so that's not a big deal. getting a new battery for that iphone would probably end up costing more in the end that your suggestion. Very good suggestion! :)this questions should show up as "answered", eh? 😉

Let it charge from mains for a couple hours and see what happens. If still a problem, try recovery mode... http://support.apple.com/kb/HT1808

Restore failed... Error 23 occured

May be a hardware failure... http://discussions.apple.com/search.jspa?search=Go&q=%22error+23%22

Based upon everything you've said so far, I'd quit wasting my time with it, unless you just like the challenge. FYI, you can get a refurb 3GS from AT&T for $79.

With, of course. See for yourself... http://www.wireless.att.com/cell-phone-service/cell-phones/apple.jsp