confirm tinyumbrella procesure to preserve baseband

[mayakukla]

i4 4.0 01.59.00------->4.21 with preservation of baseband.

Do I save shsh with tu, put the phone into DFU, start TSS server and shift click restore?

Will I need to kick the phone out with TU later?

Can anyone confirm?

 

[PsstGreek]

To do this you need your host files edited. Along with running Tinyumbrella.

When iTunes hit shift+update or option+update and select the 4.2.1 ipsw. If you hit restore the baseband will upgrade.

Look here: https://forums.macrumors.com/threads/1086025/