There is no better example of a risk-versus-reward scenario than jailbreaking your iPhone or rooting your Android phone. While both jailbreaking and rooting undoubtedly has its advantages, this possibility of something going wrong and you ending up with a 500-dollar doorstop is never too far out of mind.
Just last week, I jailbroke my iPhone 4 and succeeded with no visible damage. But as I was riding high on overconfidence, I went ahead and tried to downgrade iOS 6 to iOS 5.1 (without a backup of the old iOS on my computer) and ended up having to restore my phone to its factory settings. For you guys that tried to root your Samsung Galaxy S III and failed, you probably got "bricked"...
- Phone boots and shows the Samsung screen and then it automatically turns off.
- Phone won't turn on but shows the third-party root program's download screen.
- The phone keeps on restarting (with vibrations) after the Samsung logo appears.
- The phone is totally dead, unresponsive or no visible signs of life.
If you have a bricked Samsung Galaxy S3 and you're able to at least get into Download mode, you may still be able to save your device.
There are actually a few methods you could try in order to save your phone from complete corruption.
First, when in Recovery Mode (hold Home, Volume Up and Power), you can completely wipe the data and factory restore your phone.
Second, if you are able to access Download Mode, then you can go ahead and try to install your device's original firmware. Since your device is still technically rooted, you might be able to roll back your changes by root-installing the same hardware you were trying to get rid off. For this, you will need ODIN and the corresponding ROM for your device. Then go through the same rooting steps you normally would.
Here is a nice video walkthrough on how to recover your bricked Samsung Galaxy S III.