Root TWRP Bootloop fix after update/OTA

[nicospanas]

Since it appears you rooted and installed recovery via an app it is possible that the recovery installed is not configured properly for your device. However, as @Curtis1973 indicated you have TWRP so you should be okay.

Here are links to download SU and busybox. For busybox my preference is stericson version but again just my thoughts.

http://forum.xda-developers.com/showthread.php?t=1538053 - SuperUser zip file

http://forum.xda-developers.com/showthread.php?t=1929852 - Busybox zip file

Place these on your external SD card. From TWRP select install then select SU zip file followed by Busybox.

If install works you will have root when you reboot device.

Good Luck!!

Only just before I read your message I had managed to install superuser zip from TWRP boot screen. I downloaded from SU-Busybox-Installer.zip - XDA Developers.

Sadly, although superuser was installed successfully, I still appear to be NOT rooted. I tried to use purple drake again but it fails. I think it is because it tries again to boot via TWRP. The TWRP boot logo appears at restart and then it fails with a message that is too fast to read (maybe something like Fake SU or something). I wonder if it is TWRP that is causing all the problem and if there is a way to remove it.

As I said the TWRP app cannot be used if you are not rooted so I cannot even try to restore the backup I did. What can I do? I wish I could get to a state before rooting and without TWRP (and the boot screen). Is there a way to do that without factory reset? Curtis1973 says that even with factory reset the TWRP will still be there. Is there a way to remove it?

 

[Curtis1973]

Hmm. Your device should be able to install any update from the manufacturer of device via fastboot or download mode either using software from company or just read directly from sdcard in either of those modes. Depends on device. Some chinese off brand stuff uses fastboot which is weird and others use download mode. Point being your manufacturer may have an image of the original install on their site you can use to fix the device restoring it to factory with original recovery. You will have to check out their site and see what downloads are up for your device. Volume up plus power button enters download mode for many devices. Will either need to be usb tethered to pc with all instslled software needed and knowledge to run the procedure and install image or in many cases just have the image on the sdcard in root of card

 

[nicospanas]

While trying several things I managed to root my tablet again using LG One Click Root. So now the case is: How to remove the custom TWRP recovery so that it does not interfere with the update and how to properly unroot the tablet in order to upgrade to lollipop. I haven't found firmware on LG's site for my model.

 

[nicospanas]

I found the website that I had used the first time I rooted and installed TWRP: http://www.droidviews.com/root-lg-g-pad-7-v400-v410-and-install-twrp-recovery/

Is there a way to unroot the tablet with the custom recovery given at this site for my model?

 

[nicospanas]

After a lot of reading, some things have started slowly to make sense. I was really confused and stressed when we started. Anyway, I think in order to update, I have to follow these steps:

1. Find a stock recovery image and flash it using flashify.
2. Restore to factory defaults via the tablet's settings option, in order to un-root (since I can't find another way).
3. Let software update proceed with the upgrade.

Please correct me if I'm wrong.
I think there is a stock recovery image here.

 

[bkttk2]

After a lot of reading, some things have started slowly to make sense. I was really confused and stressed when we started. Anyway, I think in order to update, I have to follow these steps:

1. Find a stock recovery image and flash it using flashify.
2. Restore to factory defaults via the tablet's settings option, in order to un-root (since I can't find another way).
3. Let software update proceed with the upgrade.

Please correct me if I'm wrong.
I think there is a stock recovery image here.

If instructions are for your exact device then I would recommend reading the main post then when done read the main post again.

Not being rude but when you are following guidance for something you may be unfamiliar with (even when you are familiar) it is a good idea to read through the process more than once. Mainly to ensure you have a good idea of processes and what to expect, but most importantly so that you have all files (in the right locations) before you begin.

Couple of comments, for clarification only, on your numbered items.

1. This step is fine if flashify works and you are comfortable using it.
2. Factory restore may not work as you want depending on method device was rooted. If root method placed superuser app within system directory SU will still be present after a factor reset. I would suggest following guidance in link you provided. There is a comment on unrooting using SU app.

Be sure you have installed stock recovery before you unroot the device.

3. Install your update

I understand your frustration on getting things working to your liking; however, you have learned a lot during the process. Yes it is frustrating but it is how most of us have learned.

Think you have identified what needs done. Good Luck and let us know how things work out.

 

[nicospanas]

2. Factory restore may not work as you want depending on method device was rooted. If root method placed superuser app within system directory SU will still be present after a factor reset. I would suggest following guidance in link you provided. There is a comment on unrooting using SU app.
.

Your comment made me wonder if I could then skip flashing the stock rom as it is rooted and I couldn't find any that it is not. My tablet is rooted but I have never deleted anything that came pre-installed. Could I just then flash the stock recovery and try to unroot with SU as suggested in the other thread I mentioned? (I made the same question there and waiting).

 

[nicospanas]

Bricked . I finally managed to unroot it and flashed the stock recovery, but LG tried to force the upgrade and the tablet got stuck to fastboot menu. Only 3 options (restart, power off, restart bootloader) all lead to fastboot menu again. Hard reset to factory also leads to fastboot. PC doesn't recognize it. With difficulty I can get to download mode. That's only when tried to use LGMobile Support Tool where I can start the process for upgrade recover but it hangs. My tiny last hope is that I may be able to do something with LG flash tool, but I can't find the files for my model. Only for v400 (mine is LG G-Pad 7.0 V410). I'll keep reading but there is so little for my model...

 

[HasH_BrowN]

Bricked . I finally managed to unroot it and flashed the stock recovery, but LG tried to force the upgrade and the tablet got stuck to fastboot menu. Only 3 options (restart, power off, restart bootloader) all lead to fastboot menu again. Hard reset to factory also leads to fastboot. PC doesn't recognize it. With difficulty I can get to download mode. That's only when tried to use LGMobile Support Tool where I can start the process for upgrade recover but it hangs. My tiny last hope is that I may be able to do something with LG flash tool, but I can't find the files for my model. Only for v400 (mine is LG G-Pad 7.0 V410). I'll keep reading but there is so little for my model...

Well your in a soft brick. There is still hope. I'm in a hurry right now, but I am sure one our seasoned members will chime with the steps necessary to fix it. Just be patient.

 

[Curtis1973]

Yeah all LG has up for that model is a notice for the lollipop upgrade. The software has to be downloaded through the devices update feature in settings. No image files available that I can find. However a call to LG may get you an unpublished link to it. Tell them your device rebooted in to fastboot mode and wont do anything else.

 

[nicospanas]

Called LG but they don't have a link. Also searched around the internet all day, there is no KDZ or TOT files for my model. Only a rooted stock zip. Is there a way to flash it with some tool? I can get to download mode, though it doesn't really connect properly (I get an error in the device manager), and I have the latest LG drivers installed for my model.

Also, in worse case scenario, if there is nothing that can be done, what could happen if I flash it with the rom of a similar model, instead of sending it to the bin? There is the image from the previous model V400.

 

[HasH_BrowN]

Called LG but they don't have a link. Also searched around the internet all day, there is no KDZ or TOT files for my model. Only a rooted stock zip. Is there a way to flash it with some tool? I can get to download mode, though it doesn't really connect properly (I get an error in the device manager), and I have the latest LG drivers installed for my model.

Also, in worse case scenario, if there is nothing that can be done, what could happen if I flash it with the rom of a similar model, instead of sending it to the bin? There is the image from the previous model V400.

I'm on a break.

1. Take your TWRP.zip and extract the recovery.img file.
2. Place it in the same directory that you have adb and fastboot in. (You should already have these on your PC from earlier).
3. In that same directory (fastboot is in) press left shift + right mouse button to open a CMD prompt.
4. Now get your device into fastboot.
5. Then in CMD type in FASTBOOT DEVICES (doesn't need to be capitalized) then enter.
6. EDIT (COMMANDS ARE CORRECTED)Once device is recognized type in FASTBOOT FLASH RECOVERY RECOVEY.IMG.
7. Once done. Type FASTBOOT REBOOT.
8. Now enter recovery and flash the "good" rom you have through recovery!!

Those steps are for Windows PC, Linux should be similar.
Also, ONLY FLASH FILES THAT ARE MEANT FOR YOUR DEVICE!!

 

[Curtis1973]

If all else fails and mean all else....find the specs for the v400 and then compare them with your model. See whats the same and whats not. Hopefully it wont be much outside yours having extra memory and a different camera or something. If they have the same processor etc then the v400 rom may be your last resort option. I would make it a last resort though.

 

[HasH_BrowN]

The v400 doesn't have data, just wifi. No SIM card.
Actually that and a slight difference in weight/size. They are identical. Same chipset, etc.

 

[nicospanas]

I'm on a break.
Take your TWRP.zip and extract the recovery.img file and place it in the same directory that you have adb and fastboot in. (You should already have these on your PC from earlier). In that same directory (fastboot is in) press left shift + right mouse button to open a CMD prompt. Now get your device into fastboot. Then in CMD type in FASTBOOT DEVICES (doesn't need to be capitalized) then enter. Once device is recognized type in FASTBOOT RECOVERY FLASH RECOVEY.IMG. Once done. Type FASTBOOT REBOOT RECOVERY. Now just flash the "good" rom you have through recovery!!
Those steps are for Windows PC, Linux should be similar.
Also, ONLY FLASH FILES THAT ARE MEANT FOR YOUR DEVICE!!

I'm gonna need some more details. First, when you say the TWRP.zip for the recovery image file do you mean the one from here (scroll down to "install TWRP Recovery......")? Because I had already flashed a stock recovery image before this happened. So which image should I put, the TWRP custom or the stock? I also don't have a directory for adb and fastboot. I have installed on my PC an application called "Minimal ADB and Fastboot", but I don't know if that is what you mean. Anyway the application is installed in program files (x86). Do you mean that directory? And lastly, when you say to type FASTBOOT RECOVERY FLASH RECOVrY.IMG, does the image has to be renamed as "recovery.img"?

 

[HasH_BrowN]

Look here http://pdadb.net/index.php?m=specs&id=6491&c=lg_v410_g_pad_7.0_lte_lg_e7 then where it says chipset
Tap on the "browse devices..." (look at photo)
Itll pull up ~40 devices matching chipset.

(Not for the feint of heart)
Or you can do an advanced search and narrow it down even more by using this link http://pdadb.net/index.php?m=pdamaster&posted=1&cpu=a8926#form

 

[HasH_BrowN]

I'm gonna need some more details. First, when you say the TWRP.zip for the recovery image file do you mean the one from here (scroll down to "install TWRP Recovery......")? Because I had already flashed a stock recovery image before this happened. So which image should I put, the TWRP custom or the stock? I also don't have a directory for adb and fastboot. I have installed on my PC an application called "Minimal ADB and Fastboot", but I don't know if that is what you mean. Anyway the application is installed in program files (x86). Do you mean that directory? And lastly, when you say to type FASTBOOT RECOVERY FLASH RECOVrY.IMG, does the image has to be renamed as "recovery.img"?

TWRP recovery image, not stock.
Minimal fastboot will work fine, place the extracted TWRP recovery .img in same directory.
Doesn't matter where as long as .img file is in same folder/directory.
You can change the name, but whatever the name is thats what you type.
(Back @ work now, sorry for short response)

 

[nicospanas]

Look here http://pdadb.net/index.php?m=specs&id=6491&c=lg_v410_g_pad_7.0_lte_lg_e7 then where it says chipset
Tap on the "browse devices..." (look at photo)
Itll pull up ~40 devices matching chipset.
View attachment 93961


(Not for the feint of heart)
Or you can do an advanced search and narrow it down even more by using this link http://pdadb.net/index.php?m=pdamaster&posted=1&cpu=a8926#form
View attachment 93962

You lost me here.

TWRP recovery image, not stock.
Minimal fastboot will work fine, place the extracted TWRP recovery .img in same directory.
Doesn't matter where as long as .img file is in same folder/directory.
You can change the name, but whatever the name is thats what you type.
(Back @ work now, sorry for short response)

Sadly it didn't work. I did everything you said but the tablet is still in fastboot. At the bottom of the screen it says LOCK STATE - locked.

Here is what was written on the cmd:

 

[HasH_BrowN]

NVM, wrong info

 

[nicospanas]

If you look again, you'll see that I have included ".img" at the end and also I had renamed my image into recovery.img

Do I have to use .img to the second command as well? (FASTBOOT REBOOT RECOVERY)

 

[HasH_BrowN]

If you look again, you'll see that I have included ".img" at the end and also I had renamed my image into recovery.img

Do I have to use .img to the second command as well? (FASTBOOT REBOOT RECOVERY)

I posted it wrong above. Please forgive me on that.
Here is the correct command

fastboot flash recovery recover.img

Then

fastboot reboot

Then press key combo to enter recovery

 

[nicospanas]

NVM, wrong info

I posted it wrong above. Please forgive me on that.
Here is the correct command

fastboot flash recovery recover.img

Then

fastboot reboot

Then press key combo to enter recovery

The first command seems to have gone through, but not the second. Do I need to use .img at the end of the second command, too?

EDIT: sorry I just show your full message, second command also went through. I'm checking it now.

 

[HasH_BrowN]

Second command in #46

fastboot reboot

 

[nicospanas]

TWRP recovery is installed!!! I never thought I'd be happy to see the logo again. Doesn't recognize my ext. SD where I have the stock zip. Should I try and see if I can boot to the system by using the commands at the beginning of this thread?

Or should I move the stock zip from the external to the internal with DP Tools? I'm so exited that I am afraid to proceed!


EDIT: I managed to boot into system with the commands! Everything is there! Seems to work fine. You are my God! Can't thank you enough!

LG is still trying to push the update, which usually it does automatically at some point. I don't mind the update but I don't know why it fails. There is no unrooted stock rom for my tablet.
I unrooted it via the superuser app, however when I was in download mode it was showing as rooted. I may try tomorrow again do it with LgMobile Support tool. Maybe now that the tablet is working it won't fail. I'm tired now, after 3 days of struggle with the dam thing. Anyway, thanks a lot again, really appreciate it.

 

[nicospanas]

I'm officially on android 5.02! At last! It took me some time and had to reset to factory, but that is a minor issue. Also I found out what caused the softbrick yesterday. Flashify was failing to install the stock recovery. It failed again today. You guys can imagine my shock when I saw fastboot menu again. Anyway, I manage to install the stock recovery with adb, following HasH_BrowN's instructions (see how many things you taught me?). The update took place smoothly.

I'd like to thank everyone again for your help and patience. Saved my bacon!