unlocking iphone 4 using saved SHSH

[tre87]

Hi there,

I have an iphone 4 with ios 5.1.1 and baseband 04.12.01
My iphone does not support the factory unlock as it is from Venezuela, but I heard that if you have the SHSH you could downgrade the baseband and therefore unlock.
I had checked the Tiny umbrella and I have three SHSH saved..
Could anyone explain me how to do this?

THanks so much

 

[willerz2]

SHSH blobs have nothing to do with baseband downgrading, and the only baseband that can be downgraded is the iPhone 3GS with a flashed iPad Baseband on the old bootrom, and certain new bootrom 3GS's. The iPhone 4 cannot be software unlocked using UltraSn0w like the 3GS can UNLESS your baseband is 01.59.00, which is an old old old baseband. The only way to unlock a Venezuelan iPhone from my knowledge, is to use a backdoor unlock. Where and how to get it, I won't tell you since it's not condoned by iPhoneForums.