It was just yesterday when I was installing new set of Google Apps of jellybean 4.2 firmware in my Samsung Galaxy nexus I9250 GSM version of smartphone and it actually messed up my phone as I was welcomed by hell lot of force close errors after installing the Google Apps Zip package in recovery mode. So, now the first thing I would search to do is to find for the Stock / official Jellybean 4.1.2 firmware which was released by Google Inc. for Galaxy nexus 4.1.2. So just in case if you too gets into this shape then this article will help you get on to the original firmware of Jellybean 4.1.2 of JZO54K build with a simple tutorial.
Disclaimer: Follow all the instructions carefully mentioned in this article, we should not be held responsible in any manner if your Samsung GALAXY Nexus doesn’t boot up or gets bricked due to not following the instructions.
As this is the custom ROM firmware, you will have to make sure that your device will have to be rooted. To check on whether your device is rooted or not, you will have to download the “Root Checker” app from the Google PLAY Store.
Though if you are getting force close error at launcher side itself, you can’t get into the device for backing up the data, so what you can do here is connect your device to the computer with the help of original USB cable and transfer few folders like “DCIM”, Music and other files which you feel that its relevant to your computer. If there are any messages then unfortunately those will be lost.
Just in case if you are able to start your phone with few force close errors, then you can manually back up the data with the help of below mentioned steps,
SMS – Use “SMS Backup & Restore app”,
Contacts – Sync with the Gmail application,
Call Log – Call Log and Restore
Images, Songs, Videos, Files – Copy to internal / External SD Card,
APN and MMS Settings – Note down from the path “Applications > Settings > Wireless and Network > Mobile Networks > Access Point Names”
From the path “Settings > Applications > Development > USB debugging”, enable the USB Debugging, ensure that the USB debugging option is ticked. Ensure that battery charge is not less than 40% so as to make sure that it doesn’t get turned off in the middle of firmware update.
So assuming that if you are done with the above mentioned steps, you can now head over to the next page where we have summed up a detailed tutorial with which you can re update your Nexus with the Original Jellybean 4.1.2 firmware.