iPhone 3G 6.15 bootrom

[catbirdman]

Hello,

I recently was given (lucky -_- ) and iphone 3g stuck on iOS 4.1 and it couldn't be unlocked. I obviously upgraded to 4.2.1 and also upped the bootrom to 6.15 to unlock it, it works now.

Problem is, iOS 4.2.1 is horrible on the 3G. My applications frequently mess up, I have to reboot alot, etc.

I didn't have SHSH blobs backed up because it was given to me.

Can I downgrade to a different FW (custom) without SHSH blobs? I would love to just get out of 4.2.1 to an older FW that runs better on the iPhone but I don't think it's possible (a custom firmware).

Or is it possible? Do I have any options?

Thanks

[iYeow]

Yes, you can downgrade to any OS 3.xx without the need of shsh blobs.
Go with 3.1.3 for speed and performance and hassle free.

[Stray]

If it is the 3G then I guess it is your lucky day because you do not need shsh's to downgrade (pretty sure on that)
Here is a link to downgrade
» felixbruns.de
This is for the firmware
I'm pretty sure when downgrading your going to get the 1015 error so here is a link to tiny umbrella to kick it out of recovery mode
The Firmware Umbrella - TinyUmbrella

Man iyeow you just beat me I was in the middle of typing this.

[catbirdman]

Oh wow, fantastic. Thank you both. That made my day. I love the jailbreaking community. So worth donating.

[Stray]

No problem. Just helping another MMI member.

[catbirdman]

Thanks again, just downloaded the firmware. Will try it now!

But wait, when I upgraded to version 6.15 (Bootrom) it said I could never use a stock firmware again. What I just downloaded from Flexi was a stock 3.1.3.

What would I need to do to it to make it safe?

Then I just shift+click iTunes to restore, use tiny umbrella to get it back running....

Then Jailbreak it (Spirit) and unlock it .... ????? (How would I unlock it, with whatever is 6.15 compat?)