My cell phone is a Samsung Galaxy S3 mod. GT-I9300. Locked for Digitel (Venezuela mobile carrier). Android Stock Rom version: 4.1.2.
I bought this cellular a year ago, and it worked flawlessly almost for 12 months straight. I haven't experienced any single freezing or rebooting problem. I downloaded KIES and the program detected that a new version of Android was available for downloading for my phone. Bump! Error. I should have backed up my EFS first before doing the upgrading. BACKUP YOURS, IMPORTANT!)
NOTE: Backup your personal data as well since any ROM installation will remove for sure your personal data and info.
After upgrading and a few days later, my cellphone started to act somewhat funny. I started to got some freezing. To be specifically, my phone started to freeze, the screen just froze and nothing happened when I touched the screen, pressed any button. The only thing worked was to restart the cell (by pressing and holding the POWER button or by removing the batteries). Anyway, the freaking freezing problems continue occurring.
By the way, the warranty expired just a few days ago...
Since I couldn't do anything to stop the freezing problems, I decided to root the cell and install a new version of Android not official for Samsung and test its performance. But before that, I factory reset my cellphone, but it didn't work at all.
I tested several Android version I could find on internet: cm-11-20140....-i9300.zip, specifically, the SNAPSHOT, STABLE, NIGHTLY version. None of that worked, I also tested the cm-10-20... without luck. In fact, the freezing problems with those versions got worse and worse.
Taking the above in consideration, I decided to re-install the stock rom version (ver. 4.1.0) the one that was shipped with my phone when I bought it. You can find these version for any carrier in the world at: sammobile
I flashed and I used it for almost a day or so. During that period of time, I could feel that the freezing issues were gone, not even a freezing event. But unfortunately, I couldn't connect to any Mobile Network!!, so I had just bricked my cell phone !!! I took it to the cell carrier company (DIGITEL) and they could not do anything since my warranty already expired. WTF ! I was alone with my own problem now to sort it out.
By no means I mean this is a cure but I have just stopped getting the hellish freezing and rebooting problems, and I just wanna share my experience with you so maybe I could help you to get rid of this annoying issues for the time being.
Picking up where I was left off, all I had was my bricked phone and a working ROM: ver. 4.1.2, So I decided to to reinstall this version back on my phone and see if it connected to the mobile carrier.
I reinstalled it and of course, after erasing cache partitions and making a factory reset. The procedures to install any ROM on your cellphone you can find it on internet (for instance, youtube may help a lot).
After I installed the version 4.1.2. my cellphone could connect to the mobile carrier once again... phewww!! But the freezing problems continued to appear in the fuc# phone. Well, now the only option I had to test thoroughly my cell was to install any application one after another but testing if the application was the culprit for the freezing issue.
But right after installing the stock Rom, I got a error message when my phone run to the first screen (Home Screen): TOUCHWIZ stopped responding... it lit my LIGHT BULB! I searched the web for the TOUCHWIZ and found out reports regarding many problems with Touchwiz.
Holy craps! The TOUCHWIZ is a BUGGY APPLICATION that comes with the STOCK ROM developed by SAMSUNG.
My friends there is no way to UNINSTALL that application but to use another LAUNCHER. I fired up and decided to download KIT KAT Launcher. Well, I downloaded the launcher and when you first run this application a windows pops up so you can decide what launcher the cellphone may use and the time to use it. I select ALWAYS I press the HOME button, the launcher to use is KIT KAT.
In addition to that I disable various stuffs, follows (you have to go through the setting app):
Disable Touch wiz (delete CACHE, and FORCE STOP)
Disable Multi Windows
Disable Swipe Lock ( I found my cellphone freezes a lot while this is on)
I don't use a lot of widgets... but only one: The Clock and Alarm widget.
So far (it has passed 5 days straight without freezing). My phone froze on me while I was downloading something (maybe the phone was updating an app) and at the same time I was texting someone. I am suspicious that there is something to do with the downloading system too and the phone that could trigger a freeze.
Anyway, if you have experienced the freezing issue on your Galaxy S3 just like me, then try what I just outlined and give it a test. But do not download a bunch of program at the same time, just pick one by one, and allow some time to test your application and check if your phone is stable before continue with the next app to download and so forth. I have downloaded so far: whatsapp, BBM, sudoku and other games.
Hope you can get rid of the freezing problems just the way I did, any question feel free to ask.
I will continue posting any advance with my phone.
PS: excuse my standard English.