I had rooted my sprint s5 a while back, following these instructions, and all was well. I could use Titanium Backup, and view the system logs with catlog and osmonitor and whatnot. But after a year and some months, things changed a little bit for the worse. Signal wouldn't let me answer calls from other signal users; instead it would say "missed call from..". I started looking at the system logs and found thousands of entries none of which seemed to be related to how I had been using the phone. But the thing that was annoying me the most was SmartFace - unchecking it in Settings did not disable it. So I thought maybe I should do a factory reset and re-root the phone later. So I did. But it didn't really "take". I had CPL2 installed, and had rooted it with twrp and SuperSU per these instructions. So I re-read the instructions several times, and I thought hey maybe if I install a newer stock ROM, it would be like installing the original factory ROM, but after running the OTA updates. So I installed CQD1 with Odin, and after the phone was unrooted and indicated the update was successful. But nothing had been erased. All of my apps and data were intact, I didn't have to fool around restoring from Samsung account or Google account or Titanium Backup Pro. Everything is fine, but boring. I can't view the system logs, or use TB to freeze apps. So I re-rooted, and can do those things again. But then the Eye in the status bar came back. SmartFace is not enabled. So that makes me think I really should do a factory reset for real.
Here is my question: what are people referring to when they say "factory reset"? Is it going to the Settings app, then Backup and Restore, then selecting Factory Reset with or without wipe data? Or is it rebooting into recovery mode and then selecting factory reset from a menu?
And what about encryption? I successfully unencrypted my add-on sdcard beforehand, but the built-in sdcard is still encrypted and there is no option to unencrypt it. I thought installing a different ROM would erase all that stuff. Furthermore, as if to deliberately create uncertainty and doubt, when you try to do a factory reset from Settings, it tells me all my personal data will be erased and cannot be recovered! I thought that one of the main reasons for having a Google or Samsung account was to recover my personal data if I lost my phone and had to replace it, or if I had to do a factory reset. Call me dense, dumb, or long-winded, but what am I missing about factory resets or installing stock sprint ROMs? After installing CQD1, it went through a process of updating all the apps, with the animated icon of meshed gears. I was like, hey I didn't want a software update, I wanted a fresh install! And wouldn't you be shocked to learn that after re-rooting, the eye in the status bar started turning on again?
The answer is probably that to do a factory reset, the phone must have the original stock ROM installed, then do a factory reset and wipe data, then if that works, upgrade to the latest stock ROM, then if that works log in to your Google account and tell it to restore your personal account data.
Where is the 'thank' button people refer to? Because I would like to express gratitude for all the information and shared experiences I found here.