On Monday the Dev Team released redsn0w 0.9.14 beta 1, the first version of redsn0w that allows users to downgrade the baseband 06.15.00 of the iPad tablet installed on iPhone 3G and iPhone 3GS. The process is simple to do, it works from the start only on certain terminals, but unfortunately the Dev Team warned users that on some devices the process might not work at all, even though they are compatible. There are situations in which your terminal should be theoretically compatible, but still redsn0w does not downgrade and if after several attempts you have not succeeded in downgrading, then there is a possibility that you will never be able to downgrade because redsn0w simply does not can do this. MuscleNerd does not offer any clear explanation for this, but simply says that the process can fail sometimes and on certain terminals not work.
If you've just started to downgrade and the process didn't work on the first try, then you have to try the whole process again until it works, but make sure you're connected to the Internet and redsn0w has access through your firewall. If you managed to downgrade the baseband, but you have displayed the message No Service and you have no signal, then remove the card from the terminal, uninstall ultrasn0w and mobilesubstrate, reset the device, reinstall mobilesubstrate, insert the card, reinstall ultrasn0w, reset the terminal and the device should be decoded.
If after following the instructions the process does not decode your device, then you are in the situation explained in the first paragraph and you may not be able to downgrade/unlock at all.
