Root Soft bricked, rooted, can't install TWRP Recovery via fastboot

[PhoxOMatic]

Howdy all! First time poster here but long time lurker/searcher (probably going back to when I was learning how to root my Verizon original Motorola Droid (A855) nearly 6 years ago (how time flies!)).

Here's what brought me here:

In a attempt to fix an issue with outgoing audio volume and quality with the Google Hangouts app on my LG Volt, I edited the mixer_paths.xml file in /system/etc and now my Volt stays stuck at the LG logo and won't boot. I did the following:

1. Installed ES File Explorer on my Volt
   
   
2. Navigated to /system/etc in ES File Explorer
   
   
3. Copied the mixer_paths.xml file to /sdcard/Downloads (or whatever the root directory is that appears when a USB cable is connected to the Volt and it shows up in Windows 7 as an MTP device)
   
   
4. Edited line 624 of the mixer_paths.xml file in Textpad on my PC to change the 'ctl name="DEC1 Volume"' value from 60 to 30 and saved it back to /sdcard/Downloads (or whatever directory that was)
   
   
5. In ES File Explorer, copied mixer_paths.xml from /sdcard/Downloads to /system/etc (I mounted /system/etc as R/W just before copying mixer_paths.xml back).

I edited mixer_paths.xml on my PC because the editor in ES File Explorer doesn't give any indication as to what line number you're currently on and figured that I could just edit it using Textpad which does give the current line number of the file being edited, but that didn't work out so well.

I can get into Download mode on my Volt by pressing Vol+ and plugging in a USB cable and can also get into the stock recovery by pressing Vol- + Power for a few seconds until "Factory Reset Processing..." appears, so it appears as though it's soft bricked. My Volt just stays at the LG logo when it tries to boot.

I'm trying to install TWRP Recovery using the 'fastboot' command of the Android SDK, but not having any luck. :-( Neither fastboot nor adb detect my Volt when I plug it into my PC with a USB cable and issue a "fastboot devices" or "adb devices" command in a command prompt window. I installed the LG United Mobile Driver 3.13.2.0, then held down Vol+ while plugging in a USB cable to my PC. I got this:

The "LGE AndroidNet USB Modem" originally said "CDC Modem".

I'm trying to go the TWRP route so I can backup my photos before doing a factory reset, reroot, etc.

I downloaded the latest Android SDK and have these at the end of my system PATH statement:

C:\android-sdk-windows\platform-tools;C:\android-sdk-windows\tools​

I'm just trying to figure out how I can get ADB and fastboot to see my Volt... or maybe there's a dedicated PC app somewhere that I can run to flash TWRP onto my Volt?

Thanks in advance for any help and/or advice you can give!

PhoxOMatic

Edit: I forgot to mention that I rooted using LG One Click Root and that my PC is a Dell XPS 8700 running Windows 7 Professional SP1 64-bit.

 

[bg4m3r]

This would be an easy fix if you had installed TWRP. Accessing fastboot requires wiping the laf partition. I think you're going to have to follow the brick recovery guide stickied above as adb will check for a signature on the img.

 

[PhoxOMatic]

This would be an easy fix if you had installed TWRP. Accessing fastboot requires wiping the laf partition. I think you're going to have to follow the brick recovery guide stickied above as adb will check for a signature on the img.

Are you saying that I need to wipe the laf partition to get fastboot to see my phone? Is there any hope of installing TWRP in the state my phone is currently in, even via something other than fastboot?

The stickied brick recovery guide involves running the LG Flash Tool and basically doing a factory reset, thus wiping out the photos I'm trying to recover from the user storage partition. Is there something I can run in either Windows or Linux that I can run to mount the user storage area and get my photos before doing a reflash back to stock, reroot, etc.?

 

[bg4m3r]

Are you saying that I need to wipe the laf partition to get fastboot to see my phone? Is there any hope of installing TWRP in the state my phone is currently in, even via something other than fastboot?

The stickied brick recovery guide involves running the LG Flash Tool and basically doing a factory reset, thus wiping out the photos I'm trying to recover from the user storage partition. Is there something I can run in either Windows or Linux that I can run to mount the user storage area and get my photos before doing a reflash back to stock, reroot, etc.?

That's exactly what I'm saying. I don't know if there's anything in the stock recovery to let you access anything, unless there's some adb commands, which I'm not familiar with.

You could try going into adb in recovery and using this command:

adb pull /mnt/sdcard \mysdcard

I don't know if it will work without the phone being fully booted. Here's the thread I got this from:
http://forum.xda-developers.com/galaxy-s2/help/how-to-mount-internal-storage-adb-t1898712

The LG drivers in the brick recovery guide should help with getting the computer to recognize it.

 

[goobert]

I had a similar issue after I screwed around with my volt to much too. The only way to fix it was Download Mode.

http://www.lg-phones.org/how-to-flash-unbrick-lg-volt-ls740.html
http://androidforums.com/threads/how-to-restore-phone-with-dl-mode.861292/

Make sure your getting every step completed when attempting this process. It's very complicated and technical to read through.

 

[bg4m3r]

I had a similar issue after I screwed around with my volt to much too. The only way to fix it was Download Mode.

http://www.lg-phones.org/how-to-flash-unbrick-lg-volt-ls740.html
http://androidforums.com/threads/how-to-restore-phone-with-dl-mode.861292/

Make sure your getting every step completed when attempting this process. It's very complicated and technical to read through.

These are outdated. Just use the brick recovery guide in the rooting forum. It's the same process, but explained better and more detailed.

 

[PhoxOMatic]

Woohoo! I got my phone back!!

It turns out that it was a permissions issue on the /system/etc/mixer_paths.xml file. When I copied this file back to /system/etc using ES File Explorer after editing it on my PC, the permissions were different than those of the other .xml files in /system/etc. For whatever reason, this stopped my Volt from booting all the way up. Once I changed the permissions to 644 using the busybox chmod command (or was it the Send_Command.exe chmod?), my Volt was able to successfully boot.

I put my Volt in download mode by pressing Vol+ while plugging in the USB cable. I then ran the Send_Command.exe that LG One Click Root runs during the rooting process.

Now, my next job is to install TWRP Recovery now that I'm able to .

Edit: I should mention that I didn't have to do a factory reset to reflash anything... just fixing the permissions on /system/etc/mixer_paths.xml got my phone back the way it was.

Edit 2: Please disregard the attachment at the bottom of this post. I posted it before realizing that I used LG One Click Root's Send_Command.exe instead of one I found in an XDA thread. Mods, please delete it if possible... thanks!

 

[HasH_BrowN]

@PhoxOMatic for future file editing try this https://play.google.com/store/apps/details?id=com.aor.droidedit, it works on the device so you eliminate having to use the PC. There is a pro version as well. This is the best (IMHO) editor for Android. It has line numbers, line wrap, supports many file extensions, plus numerous other features. It is a full fledged editor.
I was going to chime in earlier about you double checking permissions since it wasn't mentioned in the OP, but I got sidetracked 20,000 pages away (lol). Glad you got it figured out.

Make sure you flash TWRP, then make yourself a (very recommended) backup.

 

[PhoxOMatic]

Thanks everyone for responding and providing good info to know for future reference (I wasn't aware that the laf partition has to be nuked to get fastboot to see my phone, even though I didn't go that route).