What you need to know:
1- This method is basically an "upgrade" for the device since no "Update" button appears in iTunes if the device was in DFU Mode (it appears in Recovery Mode). If you can click the "Update" button in iTunes then there is no need to use this method.
2- This method only works on firmwares that can be signed by Apple (i.e. usually the latest firmware) so you might lose your jailbreak.
3- You will need a Windows machine to run this tool.
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This will fix:
  • Device is stuck on iTunes icon (Recovery Mode) or DFU Mode or Apple logo. (Try Reiboot first before trying this tool).
  • Some bootloops.
  • One time it fixed a RSOD screen, the device did not have hardware issues.
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This will NOT
  • Will not Unlock locked devices. Try this method to remove the passcode if you're jailbroken.
  • Will not remove Restrictions password. Try this.
  • Will not fix Bootloops due to hardware issues including BSOD, RSOD ..etc.
  • & it won't fix a strange but common issue in iOS 9 when the jailbroken device fails to boot after getting "storage is full" message.
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Now to the main part :)
Tutorial:
1- Download the latest firmware for your device from ipsw.me (or any firmware in green which means it can be signed by Apple).
2- Download "make_noerase_ipsw" by Clicking here and then clicking "Downlad".
3- Make sure you have enough space on Drive C of your computer. It must be more than the size of the IPSW file you downloaded in step 1.
4- Using the mouse, drag the IPSW file you downloaded in step 1 onto the exe file you downloaded in step 2.
5- Wait, this might take some time.
6- When the process is done you should see something like this. Press "Enter" to exit this program.
7- You should now see a new file in the same folder you downloaded the IPSW file from step 1. This new file should start with "UPG".
8- Enter DFU mode (or Recovery mode) in your iPhone/iPad and connect it to your computer.
9- Open iTunes then hold "Shift" and click the "Restore" button then choose the new IPSW file which starts with UPG (the one from step 7).
10- When the process is done you will find all your apps/data. Except of course jailbreak related apps and tweaks. Enjoy your device :)
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I hope someone finds this useful. Feel free to comment/ask, I'll try to help as much as possible.