I have a 3gS White 32gb
its new boot rom
i have shsh saved for 4.1 4.2.1 via tiny umbrella
my baseband is 5.11.07 ( i rely on ultrasn0w unlock)

My prob is
I flashed a custom 4.1 (created via snowbreeze)
restore went fine,and when it completed
i was in dfu mode..

Just boot tethered option of redsnow made my phone boot and everything worked fine.
But as soon as i turn off the screen on my iphone and wait for like 5 minutes
the phone mysteriously enters DFU mode
Any solution for this?
Same problem with 4.2.1 firmware
cant restore to official 4.1 as it will update my baseband

I hate to say it but:

1) Your problem sounds like it is related to issues with sn0wbreeze.
2) Due to issues like this with sn0wbreeze and their inability to properly jailbreak devices, we do not support sn0wbreeze on these forums.

Since you have the SHSHs you need, I recommend you get PwnageTool, create your own custom iOS ipsw either by installing Mac OS in a VM or by using a friend's Mac -- you cannot trust sn0wbreeze, this is very specifically one of the reasons that we don't support it here.

The phone should not end in DFU mode -- it should end in recovery mode, and the 'just boot tethered' option will kick it out of recovery. If it ended in DFU, there's something else going on and without proper restore logs (see: http://www.hackint0sh.org/f137/130802.htm) we don't have the information to check -- but even still, I can almost guarantee this has something to do with the firmware being created with sn0wbreeze -- we recommend very strongly that you either make this yourself in a VM or make it yourself on a friend's Mac.

If you post the restore log, I'll take a look, but if it really looks to be a problem with sn0wbreeze the resounding answer is going to be to use a more reliable tool that we support for creating the custom firmware.

Originally Posted by n1ckn4m3

I hate to say it but:

1) Your problem sounds like it is related to issues with sn0wbreeze.
2) Due to issues like this with sn0wbreeze and their inability to properly jailbreak devices, we do not support sn0wbreeze on these forums.

Since you have the SHSHs you need, I recommend you get PwnageTool, create your own custom iOS ipsw either by installing Mac OS in a VM or by using a friend's Mac -- you cannot trust sn0wbreeze, this is very specifically one of the reasons that we don't support it here.

The phone should not end in DFU mode -- it should end in recovery mode, and the 'just boot tethered' option will kick it out of recovery. If it ended in DFU, there's something else going on and without proper restore logs (see: http://www.hackint0sh.org/f137/130802.htm) we don't have the information to check -- but even still, I can almost guarantee this has something to do with the firmware being created with sn0wbreeze -- we recommend very strongly that you either make this yourself in a VM or make it yourself on a friend's Mac.

If you post the restore log, I'll take a look, but if it really looks to be a problem with sn0wbreeze the resounding answer is going to be to use a more reliable tool that we support for creating the custom firmware.

2011-01-13 20:11:42.421 [2424:ca0]: restore librar - Iphone 3gs

You *simply* can NEVER restore 4.1 even via custom IPSW without a 4.1 SHSH. As for why the device went into DFU mode, my best guess is it's also due to lack of SHSH - your NOR wasn't ever flashed properly, the steps in the log file relating to NOR flash don't show any error - but it's impossible that they could have succeeded.

This is a limitation of the jailbreak exploits available for the new bootrom 3GS (and newer iDevices).

If you genuinely don't have a SHSH for any iOS version than 4.2.1 then you need to hunt down an unofficial pwnagetool bundle for 3GS on 4.2.1 that doesn't install cydia or hacktivate, just prevents baseband update. This much is possible, even on a new bootrom 3GS (as long as you have a SHSH for the same iOS version). I've seen such an unofficial bundle for the iPhone 4 but not the iPhone 3GS

Thought he said he had the 4.1 SHSH and 4.2.1 SHSH saved?

Originally Posted by n1ckn4m3

Thought he said he had the 4.1 SHSH and 4.2.1 SHSH saved?

The restore log shows that he doesn't have a SHSH -

AMAuthInstallApCopyPersonalizedImg3Data: response missing entry "LLB"

The weird thing is that I would expect the log to subsequently mention

_AMAuthInstallBundleInstallPersonalizedEntry: failed to personalize img3 object

as a consequence of the first error. Maybe this is a change to the way iTunes works in v10. I would need to compare some logs to be sure.

So either the hosts file was mis-configured during restore or the user is not actually correct about having a 4.1 SHSH

The sn0wbreeze IPSW may be designed for an old bootrom 3GS. But based on the restore log it's clear that lack of SHSH is the problem.

Originally Posted by Olethros

The restore log shows that he doesn't have a SHSH -

The weird thing is that I would expect the log to subsequently mention as a consequence of the first error. Maybe this is a change to the way iTunes works in v10. I would need to compare some logs to be sure.

So either the hosts file was mis-configured during restore or the user is not actually correct about having a 4.1 SHSH

The sn0wbreeze IPSW may be designed for an old bootrom 3GS. But based on the restore log it's clear that lack of SHSH is the problem.

When i got the device it was in recovery mood,i saved shsh via Tiny umbrella by input of manual eccid.
I dont know that counts or not
but i am able to downgrade from 4.2.1 to 4.1 by by starting tss server from tiny Umbrella.

And i Used to have same problem with 4.2.1 ,that phone goes to DFU after screen time out.
Anyways , i am using the phone for a few days now ,
I installed insomniac from cydia and since then it is working fine and i m not gonna let battery drain .
Thats it for now

Saving the SHSH is only part of it.

You MUST have TSS Server running (and TinyUmbrella must report that it has a copy of the required SHSH blob) before you restore to an iOS version that Apple no longer signs.
Alternatively, if your SHSH blobs are saved to Saurik's server, you can have gs.apple.com redirected to saurik's server via modifying the hosts file - then you can restore to iOS versions where you have a SHSH blob unique to your device backed up on Saurik's server.

If you go to DFU mode when the screen times out (ie sleep mode) even with a non jailbroken 4.2.1 then this indicates a problem with your iPhone's NOR chip.