Help with LG G3 Android upgrade

[Nelat1983]

Hi

I just bought a used LG G3. D855 (16gb)

I reset it and everything works fine.
But, it can't upgrade from it's Android Version 4.4.2.

I get a message saying there's an upgrade ready, but it won't download/install it.
I used LG's PC Suite etc. and also get a message saying it can't install newer upgrades, or that is is running the latest version possible.

Can anyone explain what is wrong here?
From what I can read, it's because the phone is rooted? and/or is an old version which doesn't have access to newer android versions?

I have read about rooting/unrooting and flashing to 5.0 and 6.0 Android, but not sure how to get past this problem, without risking having a working phone.

Flashing and rooting can be done, but can anyone give some advice to how etc.

Any help and suggestions is appriciated!

Thanks
Regards
Nell

 

[Rukbat]

Oops, bingo, magic word - rooted.

Depending on what was done when the phone was rooted, even if you remove su (which is really all that rooting is - getting su into a particular system folder somehow - you can't unless you have root, which is what you're trying to do ... Catch 22), you could turn the phone into a doorstop by updating it. So if there's any sign that it was ever rooted, the best you can get is that forcing an update package into it will fail. Which is a good thing - better an older - working - version than a dead phone.

If you want to update, you'll have to flash the stock ROM (which means backing everything up, because the stock ROM doesn't come with your pictures, your music, etc.), so you might as well flash the latest version and be done with it. But first, if having a rooted phone is important to you (it depends on why you rooted it - I can't run Linux without root access when I need it, it feels like running after both legs were amputated), make sure that there's a root method for the D855 for the version you're going to update to. It's different for each update. (Even a simple "security update" will usually patch the exploit that allowed rooting the previous ROM - rooting is considered to be a security hole, and for 99.99% of phone users, it is.)