[Sprint LG G4] lokichaos:
just wanted to share my experience in downgrading my G4's software version and want to let everyone know it's possible.

using the guide by [MENTION=5471195]tabp0le[/MENTION] here: https://xdaforums.com/sprint-g4/development/rom-mellowmallow-debloated-60fps-camera-t3358340

Depending on which current version you are on you will need the official TOT to get the process going. Once you pull your cable use the MellowMallow .img (ZVB) provided by tabp0le in his original guide and his diag commands.

I have successfully downgraded two ls991's to ZVB using this method. I do not know if this will work on other variations on the phone. THE KEY POINT IS THAT I AM VERY SURE THAT WHILE ON ZVI MY ARB WAS ON ARB 4 AND I WAS ABLE TO SUCCESSFULLY DOWNGRADE TO A LOWER software. Here's the thing, my ARB STAYED THE SAME so while

ZVB is techincally ARB 2

my ARB stayed at 4.

with this in mind, you should,

be able to downgrade to ZVA.

I have not tested going from ZVI to ZVA so anyone willing to you will be trying the downgrade at your OWN RISK!

I cannot assist you if you brick your phone but at this point I don't think too many people are worried about bricking the phone especially how cheap you can pick one up. the problem remains that you will still be on a higher ARB and the existing root methods were all done on a ARB <=2 .

quick guide (using tabp0le's original instructions):

0. if you haven't yet, read tabp0le's post, download all the files including LGUP and the official TOT for whatever version you are on (if you are on ZVI then download the ZVI.tot)

1. place the ZVB .img custom rom on tabp0le's post in your internal storage default folder. I will say the MellowMallow rom he provided is a a little buggy but the trade-off to be back pre security patch for 6.0 and unlocked sim card was worth it. make sure you use the right rom for your phone. If you have a global phone use the global rom/img. I haven't tested it yet but once you are back on ZVB you should be able to flash the official ZVB TOT so you can have a completely stock LG G4 with ZVB.

2. Place phone in diag mode by dialing ##DIAG# on dialer.

3. hook your phone into pc and change your usb mode to "charge only"

4. open up LGUP, if you have all your drivers installed from tabp0le's post then you should see your phone/version pop up.

5. select the TOT for your installed version on your phone, for me it was ZVI. hit start.

6. THIS IS WHERE YOU NEED ABSOLUTE ATTENTION TO DETAIL. Your phone will reboot. Keep an eye on the completion percent. 9% is the magic number. I would recommend watching your phone though. As soon as it says "COM XX" in green YOU PULL THE USB PLUG. if done right when it pops up, you would have pulled it right at 9%. if you are late, you risk bricking your device. However I will say that I did pull it at 11% before and all I did was replug the USB and allow the software version to update/reboot my phone. everything was fine and I attempted the whole process again successfully. if you just zone out and miss the sweet spot no worries, just allow the software to update and attempt the whole process again, DO NOT TRY TO STOP THE SOFTWARE UPDATE ONCE IT'S PAST 9%.

7. did you nail it at 9%? GREAT! continue on.

8. close down LGUP and open up a command prompt and navigate to the folder with "ports.bat" from tabp0le's post. run ports.bat. the instructions are word for word from tabp0le's post so I will just quote them.

here are the commands to flash based on version:

US ROM:

GLOBAL ROM:

if done correctly the command will "process" for a minute, it will look like nothing is happening, but that's a good thing! wait for the # to re-appear after about 3 to 6 minutes. once it does type "LEAVE", unplug your phone and reboot.

VIOLA! you should be on ZVB! hope this helps give this underrated phone some new life for those out there who gave up on it.

to check your version, download Hidden Menu APK

open it up after install and select:

* SVC Menu --> Version Info

https://androidfilehost.com/?fid=745425885120746375

update next post below