With the issues many have been experiencing as a result of the recent JellyBean update, I thought this would explain why a factory reset was important and should solve most issues. I take no credit for this whatsoever, this is basically copied word for word from a post by EarlyMon but I thought it was relevant here: Experience across the forums says that it's often not overkill at all. In fact, many of us advise users to prepare for it on any known upcoming updates. Rooters learned long ago that a lot of trouble goes away by wiping the phone's cache and Dalvik cache. It's so well established that the more mature rooting communities just do on any flash install. The more advanced devs now bake those steps into installer scripts for roms and rom updates, so they don't have to hear chatter and complaints from people who skipped the steps, and also because it's simply required. When your browser gets wonky, you clear cache. Ditto for Android. Tangled cache elements cause no end of trouble, they can't help not doing so. And OTAs delivering a payload incompatible with the existing caches, more common than not, can ONLY be fixed by clearing them. Perhaps some day, OTA installer scripts will clear those areas the way better rom devs do, automatically. But until then, the only way for a non-rooted user to do it is via a factory data reset. It clears those caches but also clears out all data, and that includes user apps. So the problem isn't that the factory data reset is overkill, it's that people without a viable backup strategy are using their phones wrong, something else that experienced rooters know. And the members that whine and insist that they don't need a viable backup strategy are the ones that whine, moan, and squeal like stuck pigs that it's Android's fault that updating their new phone, after they dunked one in the tub, lost it, or got excited and rushed to buy the latest and greatest, or had to start uninstalling crap apps, that setting things up again is just so hard. No. It's their own fault if someone tells them about MyBackup Pro and SMS Backup and they stick their heads in the sand thinking that phone trouble won't strike them. Before accepting an OTA update, backup. If it happened automatically, rely on your weekly or recent backup. Then, don't even wait for trouble, just factory data reset and restore data and apps - because that's how proper updates are done. Facts, not opinions. As for the battery pull or it's equivalent, yes, great problem solver. Semiconductors can be susceptible to a semiconductor condition called latch-up. When it happens to display control signal circuitry, it manifests as a stuck pixel. When it happens in ram, pull the battery. When it happens on the rom, factory data reset and restore, and if it happens to the rom holding system components, factory data reset, install the RUU (the usual steps your carrier service will do for pernicious trouble), and restore. (And when it happens to your sd card, reformat it.) But don't expect an OTA to cause semiconductor latch-up. It may, it might, so yes, pull the battery to clear ram. But definitely expect an OTA to leave the caches scrambled because they are famous for it. Knowing what actually causes trouble or what is likely to be wrong lets you know the corrective action to take. And now you know what causes trouble. The factory data reset is the Android users best friend. Be a pal to the members and let them know about it. Backup, reset, restore. 1, 2, 3. Why? Because just like a browser, Android runs on caches, and just like on a browser, sometimes you have to clear cache. Definitely on an OTA, don't wait and play Russian Roulette hoping that trouble didn't find you. Hope this clarifies. Edit and PS - for phones with Google Wallet, go into the app and reset the Wallet there BEFORE a factory data reset. Failure to do so will result in a bricked Wallet.