How to downgrade your baseband if you are on an iPhone 4 stuck on 4.1's 2.x baseband

I put my money where my mouth is. I tested my code on my own iPhone 4 and was able to update to 4.1 without touching my baseband.

The only doctoring I did was removing my private info. The newest version of TinyUmbrella will have an added side-benefit of allowing you to update to 4.1 without the fear of baseband update. Of course, in order to downgrade back to 4.0.x you need to have your SHSH saved on Cydia or locally. Have fun :)


IMPORTANT: If you see this message in your console 
"Could not start TSS service on port 80 because you have something running on that port already!" Then TinyUmbrella cannot protect you!!! You must kill skype or teamviewer or whatever app is running and using port 80. When you run TinyUmbrella and that message does not appear, you are ready!


I have heard a few folks voice concerns about how they can downgrade their 2.x baseband to 1.59.00 on iPhone4. Here are the basic steps:

• Close TinyUmbrella (if open)
• Close iTunes (if open)
• Remove ALL lines in your hosts file that contain gs.apple.com
• Windows: Start -> cmd -> ipconfig /flushdns
• Mac: Terminal -> dscacheutil -flushcache
• Start iTunes
• Restore (NOT UPDATE) Stock 4.0.2 iPhone 4 - 4.0.2 Download

Note that this will only work while Apple is signing 4.0.2 SHSH requests. This is due to the way Apple now updates/restores Baseband Firmware for the iPhone 4 different from the way it did to prior devices. Lucky us...

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