LG G PAD X 8.0 (T-mobile) LGV521 Bootloop, Boot Verification failed, MISMATCH_SIG_LEN

[ether9]

So as the title states I bricked my LG G PAD X 8.0 while trying to root it and now it's on a bootloop with the message "Boot Verification Failed!!!" "-cause : MISMATCH_SIG_LEN."

I have searched and tried a few methods to no avail thus far. I cannot get it to start in download mode as it is not even registering on my computer. I have tried factory resetting via Power+Vol Down and then release Power and pressing it again but that has also failed and it's going back into bootloop.

I have tried using LGUP and LG flashtool but they are not detecting the device. I've looked into the BoardDiag method but they are not specifically for the GPAD. The method requires removing the battery and this G PAD either cannot remove the battery or it is very difficult to do so. It also requires shorting the pins but I'm not very sure where they are located on this device.

If anyone has resolved this or knows how to resolve please help me out. Alternative methods or expand further on how to properly perform the BoardDiag method would be greatly appreciated.

 

[bsingleto]

Input? Answers?

So as the title states I bricked my LG G PAD X 8.0 while trying to root it and now it's on a bootloop with the message "Boot Verification Failed!!!" "-cause : MISMATCH_SIG_LEN."

I have searched and tried a few methods to no avail thus far. I cannot get it to start in download mode as it is not even registering on my computer. I have tried factory resetting via Power+Vol Down and then release Power and pressing it again but that has also failed and it's going back into bootloop.

I have tried using LGUP and LG flashtool but they are not detecting the device. I've looked into the BoardDiag method but they are not specifically for the GPAD. The method requires removing the battery and this G PAD either cannot remove the battery or it is very difficult to do so. It also requires shorting the pins but I'm not very sure where they are located on this device.

If anyone has resolved this or knows how to resolve please help me out. Alternative methods or expand further on how to properly perform the BoardDiag method would be greatly appreciated.

I just did the same thing. I skipped a few steps and now the x8.0 is in a soft loop!

Have you, or do you reading this have a solution yet? Looks like I will have to put this back in the box and place it in the back of a drawer!

 

[bsingleto]

FIXED

I just did the same thing. I skipped a few steps and now the x8.0 is in a soft loop!

Have you, or do you reading this have a solution yet? Looks like I will have to put this back in the box and place it in the back of a drawer!

I FOUND THE ANSWER TO MY OWN QUESTION!

I tried doing the physical button factory reset that the device manufacture suggested on its website but this did not work, located here LIBRARY HELP. But what did help was located under SOFTWARE &FIRMWARE PC SYNC that did help.
I followed a youtube video of this guy here: lgDOTcom/us/support-mobile/lg-V521 and through watching it about five times I copied the process "" and was able to get out of the soft brick loop process where the boot screen kept repeating the vibrate with boot failed message. This next video i didn't watch, but I scanned through it and it is the process that I went through step by step in fixing it. It took over five hours total but I when through the steps this person shows in this youtube video here youtubeDOTCom/watch?v=_tOtfF6gKkg

I will post my failed attempt on my youtube channel youtubeDOTcom/channel/UCeL3q6PUn7jV_VXTewIEppQ/playlists once I upload it later if anyone is interested in seeing how i went about bricking my tablet.

You definitely do not need to pop off the back and start soldering. One tutorial did that and it did not even work.

Your welcome !