Downgrade from 4.1 to 4.01 on a never-jailbroken 3GS

[louisxv11]

I have a 3 month-old 3GS that was never jailbroken or unlocked. But it is upgraded to iOS 4.1. I want to downgrade it to 4.01 and then do JB and unlock. Lot of help on-line for that! I put it into DMU mode and then used iTunes option+restore and browsed to this file: iPhone2,1_4.0.1_8A306_Restore.ipsw. Itunes verifies it and then tells me that I cannot restore to this firmware, "the device isn't eligible for the requested build."

Okay, I read how to change the host file to make it look somewhere else for verification. But that was for those who had jailbroken theirs previously and it was to get the shsh stuff from Cydia to make it downgradable.

So, even though I do not need to restore shsh files, do I still need to do that to get iTunes to accept the older firmware again?

Thanks to anyone who can advise me. JoJ

 

[farbod21]

You must have saved your 4.0.1 SHSH blobs on the Cydia Server while Apple was signing them (Before 4.0.2 was released). Either by being JB previously and having Cydia save them or by doing it via TinyUmbrella. If you have not done either step, you will not be able to downgrade.

 

[louisxv11]

Oh dear...

 

[louisxv11]

Aren't there generic blobs that anyone can tap into?

 

[farbod21]

No it doesn't work like that. They are specific to each device.