3 ms·

Then why do people pay more money for phones that haven't been upgraded? I figured it was because you can't go backwards and the newest versions can't be unlock

by pkulak 16y ago

Then why do people pay more money for phones that haven't been upgraded? I figured it was because you can't go backwards and the newest versions can't be unlocked.

spicyj 16y ago
The newer 3GS is harder to downgrade and you also can't downgrade the baseband (modem firmware) version, but you should be able to downgrade the actual operating system without any trouble.
cmelbye 16y ago
When you try to install a firmware on your device (whether it's iOS 4.0 or iPhone OS 2.0), Apple signs the firmware using some combination of a unique identifier and other things to make sure you should be able to install it. When they release a new firmware, they typically stop signing the old firmware days or weeks afterwards, meaning you can't downgrade to it anymore. Also, there are checks on the device so even if you do manage to install it, you'll need to run certain commands to get it to boot up the first time.