iphone 3gs MB can't be untethered JB..

[nirj11]

hii...
i have iphone 3gs with ios 5.1 model MB BB 6.15 and i try to jailbreak the redsnow give me error and say "this iphone dosn't support in untethered jailbreak"
and it stop the JB
after several attempts the JB works but it tethered..
but my iphone is MB model it need to be untethered JB!
how can i fix all this??
plz help!...

 

[Intell]

The MB/MC model has no difference on the 3Gs. Mine is a MC model but was purchased on launch day in 2009 and has the old bootrom. Only 3Gs' with the old bootrom can untether. Not all MB ones are untetherable and not all MC ones are tethered.

 

[nirj11]

but all the time i JB my iphone with tethered JB and it untethered
because is old bootrom i'm sure..i have this iphone from ios 4.1 i know is old bootrom...

 

[Intell]

If you bought that iPhone new and it came with iOS 4.1, then it is an new bootrom. The last old bootrom iPhone 3Gs where made in November of 2009. iOS 4.1 came out in October of 2010.

 

[nirj11]

no the iphone is a gift from my uncle he use it before..in ios 3

 

[Applejuiced]

Download and run idetector.
It will tell you for sure if its old or new bootrom.