Help with jailbreaking and Cydia for iPhones, iPads, and iPod touches.

Pangu provides an iOS 9.0 untethered jailbreak. TaiG provides an iOS 8.4 and 8.3 untethered jailbreak.
Check @PanguTeam, @taig_jailbreak, @saurik, and /r/jailbreak for news and updates.
You can use Cydia Impactor if you need to un-jailbreak an 8.1-8.4 device without restoring.
Instructions for jailbreaking iOS 8.0-8.4.
Before asking a question, check Frequently Asked Questions to find quick answers!
How to fix some mysterious problems.

just a curiosity... why is it not possible to downgrade the baseband on any iphone? If apple updates it when a FW with a new baseband comes out, why can't we somehow put an old baseband into a custom firmware and have itunes downgrade it?

asked 12 Mar '11, 21:07

edoz's gravatar image


It's because the baseband is actually stored on a separate chip (it even has it's own CPU!). Anyway we cannot actually downgrade without exploiting the chip. The reason that the DevTeam were able to upgrade the 3GS baseband to the iPad 06.15.00, was because it is an UPGRADE, not a downgrade. So the reason that it can't be downgraded is because the baseband chip HASN'T yet been cracked. And the reason that the DevTeam haven't yet found an exploit is that they are too busy exploiting other parts of the phone, e.g to give us untethered jailbreaks or carrier unlocks.

Hope this clears things up,



answered 06 May '11, 16:14

danlocke's gravatar image


Not sure, I think you can prevent it from updating, but downgrading... I don't think so. Else a lot of people would do it.


answered 12 Mar '11, 21:18

matoetheiostream's gravatar image


yeah, everybody is saying it is not possible, but nobody is explaining why. I'd appreciate some concrete reference, if any :-) Thanks!


answered 06 May '11, 11:18

shuusaku's gravatar image


I'm with you,and don't get me wrong,I'm not complaining just curious also. There was a baseband down grade available on the 3G with fuzzyband,I wonder what the difference is and would I understand it if you explained it to me. -Just curious and extremely grateful to the hacking gods!


answered 06 May '11, 14:44

jimilee2's gravatar image


I'm not sure why either, but i have heard that musclenerd was going to work on it, but i4 unlock was priority.


answered 06 May '11, 15:23

mjandar's gravatar image


You can replace the base band chip with new one for 60$. It will roll back your bb from 6.15.0 to 5.?.?. I have seen a u tube video.


answered 06 May '11, 16:47

Rlamba's gravatar image


Serious point! when i updated lots of 3GS with 6.15.00 modem to iOS 5, BB was downgraded via itunes with no other tools!!! maybe it will help to someone :) Maybe someone can make some custom iOS 5.ipsw with unlockable modem version, and lots of ppl gets their gps back and lose extra battery drains :)


answered 27 Nov '11, 08:12

vit4lik's gravatar image


edited 02 Feb '12, 23:11

spockers's gravatar image

spockers ♦♦

The reason that fuzzyband can downgrade baseband is because theres a exploit for the 5.8 baseband bootloader theres no exploit for anything higher


answered 27 Nov '11, 17:02

1L1keTurtles's gravatar image


Your answer: (please use the "add new comment" button unless you are actually answering the original question)
toggle preview

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text]( "Title")
  • image?![alt text](/path/img.jpg "Title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported



Asked: 12 Mar '11, 21:07

Seen: 10,198 times

Last updated: 02 Feb '12, 23:11

JailbreakQA is by chpwn and comex.
About JailbreakQA. Powered by OSQA.