In order to downgrade future versions you need to have your SHSH Blobs saved. To do this you will need a few tools:
Now that we have the required tools we are going to attempt to back-up the SHSH Blobs for the device. If Apple has stopped signing the iOS you will not be able to downgrade. (If they have stopped signing the 4.3.0 iOS then your only option is a tethered Jailbreak until an untethered one is released.) Follow the following steps to back-up your SHSH Blobs:
Step #1: Put the Apple TV into DFU Mode
Easiest method I have found while doing this is to do the following:
- While the Apple TV is disconnected from the Micro USB (I would recommend leaving the USB connected to the computer just not in the Apple TV; nor do you want the power connected either), hold the Menu+Play/Pause buttons on the silver remote.
- While holding the buttons on the remote connect the micro USB cable to the Apple TV
- After 7 seconds release the Menu+Play/Pause buttons
Step #2: Now that the device is in DFU mode (if it isn’t try again), run the USBVIEW application. In the left hand pane you will see all devices connected through USB. Locate the Apple TV (it will also say DFU in the name to show that it is in fact in DFU). Select the device and in the right hand pane you will find an ECID number. Copy this to the clipboard or write it down for the next step
Step #3: Now that we have our ECID (we can close USBVIEW unless you want to monitor the Apple TV and the modes it is in during the restore) open TinyUmbrella. Once the application is loaded click the Advanced tab and uncheck “Request SHSH Blobs from Cydia”. Now click back to the General tab and click on Manual ECID. A dialog box will display, enter the ECID from earlier and as well the name of the Apple TV, generally this is “Apple TV” but you may have changed it. (I do not think this has any affect just what is displayed in the left pane.) Once the information is populated (and you have selected Apple TV in the drop down, should be defaulted to this), click Create Custom Device. Once the device is created selected it on the left hand pane and click the Save SHSH button. Within the All Saved SHSHs box it will display all the currently signed iOS that were saved and as well can be restored. Hopefully you have 4.3.0 in this list which is currently the latest iOS that has an untethered jailbreak available. Now click back to the Advanced tab and re-check “Request SHSH Blobs from Cydia”
Step #4: Now that the SHSH Blobs have been saved it is time to create the custom IPSW. First we need to force iTunes to think it is using the Apple Signature server. From within TinyUmbrella click Start TSS Server. Now open Seas0nPass. Once Seas0nPass is started hold the shift click and click Create IPSW. This will allow you to select the AppleTV2,1_4.3_8F455_Restore.ipsw that was downloaded (or hopefully you downloaded at the beginning of the tutorial). Allow Seas0nPass to create the IPSW and allow it to run an iTunes script to automatically restore.
If you receive any 16xx errors it could be cable related. I tried a few different cables before it finally worked.
If you receive a 3194 error it means that the SHSH blobs for your device were either not cached yet on Cydia or that the TinyUmbrella TSS server isn’t running or your hosts file isn’t set (to verify press the Windows Key on the keyboard and the letter R; a run dialog will open. Copy and paste the following: notepad C:\windows\system32\drivers\etc\hosts
At the bottom of the file you should see a line like this: 18.104.22.168 gs.apple.com. If you don’t close TinyUmbrella and start at Step #4. Sadly even with the custom IPSW created it will need to go through the entire process again.)
Hopefully this helps clear some things up. And if it doesn’t work the first time keep trying. It took me 4 days and countless hours for it to work. Remember to never connect the power to the device or it will cause the device to boot up. Also if you get stuck in recovery move leave the device disconnected from power for 5 minutes and then connect the device. (You need the TSS server running from TinyUmbrella) Open iTunes and click your Apple TV. Hold Shift and click Restore and select the original IPSW (AppleTV2,1_4.3_8F455_Restore.ipsw). This will flash the device back to stock and you can try again.