Many Nexus 7 owners have started receiving Android 4.2 updates OTA but unfortunately there are still many that are waiting, including myself. Here’s how you can manually download the updates and push it on to your device.
Prerequisite: Your Nexus 7 should be running Android 4.1.2 build JZO54K. You will not lose your data using this method.
Download the update zip from Google’s servers (MD5: 7bee9b220c20979763af563cad56af94)
If you have a custom recovery, you can just copy it to the device, reboot to recovery, and flash directly as you would any other zip. You’re done.
If you have the stock recovery, carry on.
Some users have also reported that the method below works
Reset Google Services Framework app:
1. Settings>Apps>Google Services Framework
2. Force Stop, Clear Data
3. Check for Update.
Reboot your Nexus 7 and hold the Volume Down button while it’s booting up.Once you see the fastbootmenu and the word Start, press Volume Up a few times until you see Recovery and then press the Power button to enter recovery.
You will see an Android with a red exclamation point. Now press Volume Up + Power together, and you should see the menu below.
Select the 2nd option called apply update from adb.
Connect the Nexus 7 to your computer with a USB cable.
Make sure you have adb. Copy the 094f6629314a.signed-nakasi-JOP40C-from-JZO54K.094f6629.zip to the same folder as adb.
Keep the file you just downloaded on your computer and open up a command prompt (cmd in Windows, regular shell in Linux and Mac) in the same directory as the zip file.
adb sideload 094f6629314a.signed-nakasi-JOP40C-from-JZO54K.094f6629.zip
You should see the progress bar go up to 100%, like so:
sending: ‘sideload’ 100%
Enjoy Android 4.2 with multi user support.