Error message (20) when restoring from 3.0 to 2.2

grifnal1

New Member
Jun 24, 2009
2
0
0
#1
I updated to 3.0, and, yes, I know, but I would like to go back to 2.2. Does anyone know how to do that? I have download 2.2 .ispw software, but everytime I attempt to install it I get an error message (20). HELP!
 

grifnal1

New Member
Jun 24, 2009
2
0
0
#3
  1. put it into DFU mode
  2. say that the iPhone needs to be restored
  3. download the 2.0 software .ispw (the firmware)
  4. hold shift while clicking restore in iTunes
  5. select the downloaded file
  6. iTunes extracts data from iPhone, but fails to install

Does that answer your question?
 
Last edited by a moderator:

fc97accord

New Member
Bronze
Oct 2, 2008
96
0
0
Vancouver
#4
I don't think you can unless you have a custome ipsw file for 2.2 with the current baseband.

I think the reason is that 3.0 has a completely different baseband to 2.2 and even 2.2.1

do a google search and you should find more info on that.
 

Adam1389

Member
Silver
Nov 20, 2008
588
1
18
Ilwaco, WA
#5
Is your phone hanging in DFU mode when you try to downgrade? If so, download QuickPWN for the firmware you are wanting and run it. It will kick it out of DFU mode and you should be set. It works with 2.2.1, so I would *guess* it will for 2.2.