iPhone 3G, unknown iOS bricked?

[manamaga]

So, I've been asked to take a look at an iphone 3G for a friend. It had been Jailbroken but they hooked it upto iTunes and ever since all they get is the USB icon on the phone. iTunes throws up the 1015 error and I've tried all kinds of ipsw, redsnow etc etc but cannot get this thing booted. Unfortunately I dont know it's current FW, all I know is that it is a 3GS, and me being me says "oh yeah, just fetch it down, I can fix it" (famous last words!!)

Please please please could anyone offer some help during this festive period :-D

[xboxbml]

Well...if u download ios 3.1.3 then hook up the phone to pc then put in DFU mode iTunes should see that, then hold down shift key n click restore n browse to 3.1.3 IPSW..it should restore that iOS...but if it has iPad baseband u have to create no baseband IPSW first with sn0wbreeze first..I forget which version...search web...

Hang on...which is it? 3G or 3GS? U said both...

[manamaga]

I forgot I posted this. I managed to get the phone up and running before but now the numpty has brought it back having locked it up AGAIN!! Trouble is, I forgot how I did it last time.

This is the info on the phone:

iPhone 3GS
Firmware 4.1
Baseband 06.15.00-6.2_M3S2

Cant restore (holding shift) to 3.1 in itunes as it says that the firmware is not compatible.

Please any help on this would be fantastic! Cheers.