[How-To] Unroot your phone and return to stock

[zefie]

This thread has been depreciated. Please see the "Sticky Threads" section at the top of this forum for updated guides with working links. Thanks.

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Otherwise you will perma-brick your phone.

Due to the increased number of bricks I have to put this announcement

When I say to flash LG Stock Recovery, it means flash LG Stock Recovery.

It does NOT mean that you can skip this step because you want custom recovery, because you want to save time, because you are lazy, because LG Recovery hates your dog... whatever.

There is a reason we are flashing back to LG's recovery.

Steps 25-29 are NOT OPTIONAL!!!!


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I have made a nandroid dump of the complete V8 stock system, including kernel, rom, recovery.. everything except the evil devil RADIO. Restoring to V8 will allow you to accept the Sprint V9 update and update your radio PROPERLY.

It will also allow you to bring your phone in for repair, or just remove any hacks you did so you can sell the phone, ect.

This is 99.9% STOCK. This returns your phone to the state it was when you opened the box.

In fact, I pulled this from a brand new Optimus, using the rageagainstthecage exploit, being sure NOT to modify /system in ANY WAY.

However, in order to restore the recovery, I had to use V9's boot and recovery. This will not effect the upgrade process from V8 to V9 in any way.

Here is what you need to do.

1) Root the Optimus. I assume you are already rooted if you are needing a total system restore.

2) Download GNM's v1.1.0 Recovery Kernel. Please use this recovery and no other as this is the only one I have tested. Use of another recovery kernel may brick your phone! Your recovery is going to be wiped with LG's recovery anyway, so don't risk it!.

3) Download flash_image.

4) Connect your optimus to your PC and prepare for ADB usage.

5) Unzip the recovery kernel and flash_image.

6) adb push recovery-RA-GNM-thunderc-s-1.1.0.img /sdcard/
7) adb push flash_image /data/local/tmp
8) adb shell
9) su
10) chmod 755 /data/local/tmp/flash_image
11) /data/local/tmp/flash_image recovery /sdcard/recovery-RA-GNM-thunderc-s-1.1.0.img
12) reboot recovery

Now you should be in GNM's recovery with aqua-colored text. The controls are: Up = VolUP, Down = VolDown, Back = Back, Select = Menu (right of home).

13) Go down to "USB-MS Toggle"
14) Select "USB-MS Toggle SDCard"
15) Download my Stock V8 Nandroid Dump
16) Unzip it into the root of the USB Device/SDCard
17) Safely remove the USB device using your PC OS.
18) Press menu to disable USB-MS Toggle.
19) Press back.
20) Select "Backup/Restore".
21) Select "Nand restore".
22) Select "mem=477M".
23) Select "BCDMRS12-20101122-1915"
24) Press menu to confirm.
25) When the process is complete, DO NOT REBOOT. Nandroid does NOT flash recovery by default, to protect from losing your custom recovery. In this case we WANT to lose it, otherwise we won't be stock, and OTA updates will not work. Therefore we must...
26) adb shell
27) mount /sdcard (if this throws an error about "device or resource busy", just ignore it)
28) cd /sdcard/nandroid/mem=477M/BCDMRS12-20101122-1915
29) flash_image recovery recovery.img
30) reboot

Now you are back to V8 stock! Enjoy!

To upgrade to V9:
Due to the kernel being from V9, the phone thinks the firmware is up to date, so you will NOT be prompted for the OTA update. However, since I have a copy of it, you can manually install it. Heres how:

1) Plug phone into PC
2) Enable USB Mass Storage
3) Download the V8 to V9 update and place it in the root of the USB Device/SDCard as "update.zip" (renaming it is important!)
4) run the following from cmd prompt: "adb reboot recovery"
5) You are now at LG's dark-blue recovery screen (should only be 4 options, if not STOP HERE)

6) Select the option with "update.zip"
7) follow instructions on screen (VERY IMPORTANT)

You now have V9 Radio/Baseband and V9 stock update. You can delete the update.zip from your SDCard when you are back into Android.

To upgrade from V9 to VC:
1) Use the LG Updater.

You now have VC Radio/Baseband and VC stock update. You can delete the update.zip from your SDCard when you are back into android.

To re-root on VC, see this thread.

 

[basketthis]

Good to know it's here if anyone ever needs it

 

[prittyboy203]

hey zefie im haven trouble trying to get the last step down i have done everything else to get to the flash the last .zip i finnaly got a laptop soo i wanted to update the radio and never got to it sooo i get a fat 0 when i came to flashing the v8 to v9 it giving me errors like no sutch file /sdcard/update.zip but it is on the sdcard i had tryed copy paste 3 times and i actually can download the update thru sprint but the battery is dead going to try with that and with the stock recovery any hints why everything is mint?

 

[prittyboy203]

sorry zefie wasnt paying attention i was going from computer naming everything .zip and i just used astro and i realized the computer wasnt showing the .zip there already was thanks for the great instrutions deff helped out when we needed it ;-)

 

[prittyboy203]

this is the best took a little trial and user error haha now im back from the doctor aka fresh and clean optimus s using these directions to the t and now once again zefie has save my buns again lol this can be done by anyone just read first over and over oh ya and over again before attempting anything lol great job

 

[smccloud]

doing this right now since my optimus is bricked atm

 

[tacke]

For smccloud...if you are successful unbricking your phone, please post here. My is bricked as well. Thanks.

 

[Fajo]

Revert back to stock

abc

 

[prittyboy203]

You can use zefies directions to get back to stock the read is called back to v8 stock just on case you have to get b radio or something like that and you can use z4root if you did or didnt and it will take away the root ether way you should do zefies directions first to get your recovery image off

Sent from my LS670 using Tapatalk

 

[trekkie1701c]

Definitely interested in seeing how many people's phones this fixes. Would make me feel a lot safer about installing a ROM on this thing

 

[Schufly]

Need some help, wifes phone is stuck in the boot loader screen, followed the directions here but CANNOT get su!!

 

[simon.ponder]

Help?

Need some help, wifes phone is stuck in the boot loader screen, followed the directions here but CANNOT get su!!

Give us as much details and errors as you can, and we may be able to assist you.

 

[neilgoldstein]

I had to restore to stock for a test at work with Active Sync. Worked great!! I assume I can put Thunder back on here after I'm done proving that our Active sync settings are wrong on the server ;-)

OK, I stand corrected. The problem was my phone. For reference: A rooted phone will join Active Sync, but the server will not be able to force a lock policy, or perform a remote wipe. Whooooops

 

[sabauman]

Directions on OP worked to the "T" Thanks!!

 

[ronnienyc]

wow, great!

WOW, you saved my ass in a major way. THANKS A MILLION!

 

[mrouttaboundsz]

why am i always the one with a problem lol. i renamed the file update.zip but when i go to apply it in the lg menu it tells me no such file exist

idk if i should but i went into system updates and its updating as i type.

 

[zefie]

why am i always the one with a problem lol. i renamed the file update.zip but when i go to apply it in the lg menu it tells me no such file exist

idk if i should but i went into system updates and its updating as i type.

that should be fine ^.^

 

[hamagc]

zefie, do we have a stock kernel floating around anywhere that can be flashed? for those of us that flash an oc kernel and want to go back without having to restore nandroid.

 

[zefie]

zefie, do we have a stock kernel floating around anywhere that can be flashed? for those of us that flash an oc kernel and want to go back without having to restore nandroid.

for now just pull the boot.img from this zip and flash it using flash_image boot boot.img

 

[Droid-One]

This worked great for me. THANKS