How to Factory Reset Your Android Phone or Tablet When It Won%u2019t Boot - How-To Geek. The feared red triangle is familiar to anyone who has ever played around with rooting and installing custom ROMs to their Android device or tablet. Many iPhone users have laughed when I described the problem, and have made clear that they never bricked an iPhone. Of course, they are the lemmings who swallow the OS Apple gives them, and have never done anything but turn them on and click icons. Whatever turns you on. I, and those like me, are adventurous types who want to push the horizon, and make our devices better. And, we do. The benefits of custom ROMs far outweigh the disadvantages; and, for the ones who do, there is always a way back to pristine stock OS. This is a very good guide to wiping the phone or tablet and bringing it back to its original state. From there, all things are possible again. Hack on.