Boot Loop.
A different kind of boot loop perhaps. I went to setting and tap on Erase All Content and Settings on my jailbroken iPad Air (iOS 8.4, A1475). And then a loading screen came up on my iPad (like the one when restoring an Apple device). Then, my iPad froze (it freeze suddenly, bricked) and an Apple logo pop up, won't go away (actually it does, the iPad keeps rebooting until I longly press the volume up button which freezes the iPad with the Apple logo and the process of rebooting repeat when I hard reset it). It's been like this for quite a while, 48+ hours. I've tried hard resetting it and restoring it but iTunes replies error 3124. I then fix the host file (not the pro way, just copy pasting stuff) and when I restore the iPad again, it return Error 3600.
P.S. It's a different boot loop becuz the solutions/fixes listed for "boot loop" on YouTube (hard resetting and restoring) or the first few websites in Google results doesn't work for me.