Today I got software update notification on my phone lolipop 5.0.2 , yeah new update to 5.1 . I am forgot what I have done to my phone , at least my phone is rooted. I am go to setting , about phone and go to System Update, thick I’m in and 161 MB update progress started.

After download finish , phone reboot to recovery mode and I remember I use CWM recovery , failed :D , then I replace the recovery image to stock, try download the system update again , then failed again :D

Since I didn’t know what happen on update process , google help me with “adb sideload”. I pick the update file , which located on /cache , copy it to sdcard and my laptop. I did “adb sideload” with update .zip file and got some nice info :

Failed To Verify Whole-File Signature Error

I try to unroot my phone (using full unroot feature on root app) and try again with system update, the result is same : Failed To Verify Whole-File Signature Error :D :D

I guest that “root” process did some modification to system file , and when System Update run , it’s check system integrity and generate that error. So I need made my phone back to stock firmware lolipop 5.0.2. Download the firmware first at XDA here , my phone is US with code LXB22.99-36 (saw on about phone info).

Doing stock firmware flash with mfastboot.exe (I keep my user data , so I didn’t do erase user data )

mfastboot.exe flash partition gpt.bin
mfastboot.exe flash motoboot motoboot.img
mfastboot.exe flash logo logo.bin
mfastboot.exe flash boot boot.img
mfastboot.exe flash recovery recovery.img
mfastboot.exe flash system system.img_sparsechunk.0
mfastboot.exe flash system system.img_sparsechunk.1
mfastboot.exe flash system system.img_sparsechunk.2
mfastboot.exe flash system system.img_sparsechunk.3
mfastboot.exe flash modem NON-HLOS.bin
mfastboot.exe erase modemst1
mfastboot.exe erase modemst2
mfastboot.exe flash fsg fsg.mbn
mfastboot.exe erase cache

After back to stock firmware , I am repeat System Update and this time , process goes smoothly , no error found and my phone upgraded to lolipop 5.2 :)