Hi,

my Iphone will not boot no matter what I do and I've tried everything I could find for the past 5 days

I've flashed it with a custom 4.2.1 without baseband (3g restore log - Pastebin.com) but it won't boot, it will just sit at the apple logo.
I've flashed it with a normal 4.2.1 just for reference (2011-08-26 18:43:00.187 [3552:de4]: restore library built Feb 7 2011 at 06:28:5 - Pastebin.com).
After kicking it out of recovery it also just sits at the apple logo.
I've also let redsn0w run in verbose boot, the last message I get is "systemShutdown false" and it will just sit there.

I'm totally out of ideads and any hint what could be wrong would be greatly appreciated.
If you need more information please just let me know.

Thanks

One more thing to add: if I flash it with 3.1.2 it shows the Apple Logo and then fades to a white screen

You know you can`t flash with iTunes after 6.15 ?

Try flashing with redsn0w_win_0.9.6rc8
with 4.2.1

Only select install cydia as you`re already on 6.15

Let us know

Since when can you flash your phone with redsn0w, I thought that was just the jailbreak software?

Originally Posted by Cherubim

Since when can you flash your phone with redsn0w, I thought that was just the jailbreak software?

When you upgrade your baseband to Ipad one (6.15) you cannot flash with iTunes anymore
Try what i sayd and let me know

Don`t choose to install cydia if you don`t whant to but you have to flash with redsnow after 6.15 Baseband

Did it, still the same.
The phone will either sit at the logo, or if I enable verbose it will sit at "systemShutdown false"

Open redsn0w_win_0.9.6rc8 got to be this one exactly, browse for iPhone1,2_4.2.1_8C148_Restore you can get it here ( iClarified - iPhone - Where To Download iPhone Firmware Files From )
de-select all options ( since you are already on 6.15 ) next and let it flash all the way till the end

got to be exactly that redsn0w version and that ipsw 4.2.1

let me know how it went

Done with the exact same versions you mentioned: stuck at apple logo while booting

does it gives you any error wile flashing?
are you using Windows or Mac?

no error at all, using Win XP