When I try to update my Nexus 7 from 4.1 (Jelly Bean) to 4.2 (also Jelly Bean) it works fine up to a point where the little android (with the rotating shape) lays down and has a red warning triangle with an exclamation point. When I press the power and VolUp buttons simultaneously to see what went wrong, the log shows this:

Verifying current system
Assert failed: apply_patch_check("EMMC:/dev/block/platform/sdhci-

I searched for the error message online and couldn't find anyone with the same problem. I even removed the random letters and numbers after "by-name" (I assume these are device-specific), and still found nothing. I also tried factory resetting and still the same problem.

I'd like to know what went wrong, and how to fix it.

  • Why did you remove the random letters and numbers? They are part of a signature check to verify the update... probably the download got corrupted, was this OTA update? If so, you may have to re-initiate the OTA download again and retry.
    – t0mm13b
    Jan 1, 2013 at 22:30
  • I have downloaded and redownloaded probably 20 times. The update probably isn't being corrupted OTA.
    – Kyle
    Jan 1, 2013 at 23:48
  • disregard my last comment - something is wrong with the boot partition! Check the first posting over on XDA Notice that the block device name refers to the /boot partition... So my question to you is this, is the bootloader unlocked?
    – t0mm13b
    Jan 1, 2013 at 23:55
  • The bootloader was locked up until about 2 minutes ago. I'm going to try installing 4.2.1 with fastboot and see if that solves the problem.
    – Kyle
    Jan 2, 2013 at 0:00
  • Good luck :) Please do report back your findings :)
    – t0mm13b
    Jan 2, 2013 at 0:00

2 Answers 2


Q- What is an assert script?

A- All it does is check to make sure you are flashing the ROM on the correct device.

How to fix Android Custom ROM Status 7 installation Abort assert failed error in Recovery Easily [Ultimate Guide]: http://mobotechie.com/tips-tricks/how-to-fix-android-custom-rom-status-7-installation-abort-assert-failed-error-in-recovery-easily-ultimate-guide

Assert failed [SOLVED]: http://forums.androidcentral.com/optimus-v-rooting-roms-hacks/182438-solved-assert-failed.html

Thanks for those cool guys, and good luck.


I don't really know what caused this problem. I had to unlock the bootloader and sideload with adb. This involved completely wiping my tablet. Here are instructions. Now my tablet updates just fine.

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