Just a moment ago, I have upgrade my iPhone 3G to firmware 2.2. My iPhone is the jailbreak version. I thought everything is okay when I upgrade it, but when I upgrade to 2.2, my iPhone can’t detect my network which is available when I’m using 2.1.
So, this is what I did:
1. Downgrade it to 2.1 again, but then I get error 1600 when I try to restore from DFU mode. This is crazy.
2. Next, what I did is to remove my SIM PIN lock(using another phone) and try to restore using normal method(recovery mode) without DFU mode. Note: if you are stuck in DFU mode, hold Power+Home for 10 sec and them power it on again normally using power button.
3. Then, I restore it to the backup that is date that dated before the 2.2 upgrade. Now, everything is fine!
Here is what I can deduce after my research on the net about iPhone error 1600:
1. This happens only to iTunes 8.0 and later.
2. This happens to jailbroken iPhone with the custom firmware(whether 2.1 or 2.2).
3. This happens when you try to restore your iPhone using DFU mode.
If the reason are like above, read below.
The solution that can be done is:
1. Downgrade iTunes 8.0 to iTunes 7.7. Here is the torrent link for Windows XP
2. Get a custom firmware (torrent this) or make your own custom firmware using Pwnage Tool for Mac.
3. DFU your iPhone the restore using iTunes 7.7 that you have DL’ed.
4. Even if you are on Mac OS X, you can just boot camp your Mac, then install the iTunes 7.7.
That’s all. Hope that can solve your problem about iPhone error 1600!
For more information, you can check the Apple support here.