Hi!
Just a few days ago my mate gave me a iPhone 3g(Black).
I used it on my network(Three G[www.three.com]) and it worked fine... Just a day ago i gave the phone to my dad, he wanted to see it.
Suddenly(he doesnt know why) the Apple logo came up and the phone went into 'no respond'.
I then connected it to iTunes(latest) and it came up again, phew i thought...
but! Since then it started playing up. No more signal. It just says 'no signal' or its just empty at the bar. (i tryed many simcards. O2(original), Tmob, three, Voda)
I thought i just get it upgraded, it might work. Its now on FW 3.0.
But it still has the same problem. (no signal and/or empty bar)
I tought of unlocking/jailbreaking it...
i downloaded:

iPhone1,2_2.2_5G77_Restore.ipsw
and

iPhone1,2_2.2.1_5H11_Restore.ipsw
Source: Download QuickPWN iPhone App

both of which i cant use.... Whenever it finishes 'extracting', an error msg comes up. Error 20.

When i try
iPhone1,2_3.0_7A341_Restore.ipsw, it works perfectly fine.
I get to the normal Home screen and can use everything, exept the network.

If theres a solution for the signal problem, i'd be happy to try it.
I also dont mind Downgrading and Jailbreaking/unlocking it and try weather it works or not.


If you guys can help me, it would be great!


thank you!


Some stuff:
Version: 3.0 (7A341)
Network: O2 4.0
Model: MB496B
Modem FW: 04.26.08

1) Restore to OS 3.0 in itunes.
2) Google for redsn0w and install it. Then run it in order to jailbrake your phone
3) In Cydia add the folowing repo: ultrasn0w.com
4) Install ultrasn0w in Cydia
5) Reboot the phone

If you need a step-by-step tutorial go to iclarified. They have some good ones.