Hi,
i have an iphone 3G from a friend and dont know what firmware was on it when i received it....
It is now restored to factory settings using "iPhone1,2_2.2.1_5H11_Restore"

Now, Its on the "Slide for emergency" screen, but the signal bars are visible on top (it doesnt say 'no signal').
Can i assume that its been unlocked before and the baseband is unlocked ??

Also, i made a custom ipsw with "activate" unchecked.

But now, when i enter dfu and try to restore from the custom ipsw, i get an error 1600

Pls help...
big thanks ....

Your phone needs activating.
What network are you trying to use it on? If it's not an official carrier (assuming it's a 3G) then you now can't use YellowSn0w as you've restored to 2.21.
You might have to wait until YellowSn0w is updated for FW3.0

I have the same problem.

I had 3.0 working and then I installed some apps from Cydia which killed my OS. I can restore to the official unpwned 3.0 but I get error 1600 if I try to restore to a pwned 3.0

I'm on my official carrier and don't use yellowsn0w.

Originally Posted by OchoCinco

I have the same problem.

I had 3.0 working and then I installed some apps from Cydia which killed my OS. I can restore to the official unpwned 3.0 but I get error 1600 if I try to restore to a pwned 3.0

I'm on my official carrier and don't use yellowsn0w.

Restore with apple original firmware and let itunes activate your phone because you are on official carrier.
Now, put phone in DFU mode and restore with your custom firmware.
Note: your custom firmware should not have "activation" check because you are on official carrier / officially activated.

I have tried that process and am still getting the same error.