H81110n update to Marshmallow fails and it can't connect in mtp mode to a PC

[musmula]

So I bought an lg g4 on eBay (yeah, I know, that's mistake number one) and it's the T-Mobile version of the g4 as far as I can tell so here are the symptoms of my problem:

I get a notification for a system update, it's been downloaded and it just asks me to start the installation process

I tap install, it starts it's little countdown and reboots the phone

The system update starts with the little android wiggling its ears and at about a third of the the filing progress bar an error gets thrown

I used to take out the battery at this point but just now when it failed again I've let it be and the phone booted normally again

There seems to be no damage done after the update failure, the phone functions almost normally (I'll get to the almost part soon)

Of course, the about phone section says I'm still on android 5.1

After googling around a bunch, I've found that people trying to help others in similar situations recommend checking for updates by going to the about phone section in the settings and tapping something like "software updates" except I don't have that. I have the update center in that section but that only offers app updates

Okay, it's no big deal, lollipop is just fine for the most part but remember how the update is downloaded automatically? Yeah, it doesn't care if I'm on WiFi or not... It's a 1GB update... It sucked my data plan dry. When I checked what drained a gig from the cellular network 'android OS' is named as the perpetrator

So I guess if there's nothing that can be done about the update, can I at least disable this mechanism?

Of course there's more, here's what I already tried to do to fix this:

Use lg bridge to force the update (didn't work because the phone can't go to mtp mode... It was set to it by default but even tho it said 'connected as mtp device' it didn't actually get recognised by the windows PC (but if I can remember correctly, it was once recognised by my Linux box (xUbuntu), and later I've set it to 'charge only' and now it won't go back))

Use the lg flash tool with the update in kdz format (the flash tool just gave me an error regarding its ability to contact 'the server' but I did wait another 10 minutes or so for it to get it together as it seems to be doing in other people's cases, not in mine tho)

Try to install the update without a SIM card and once just in airplane mode (because it's an unlocked phone and i don't use a T-Mobile SIM card)

My next try is going to be the flash tool again and then twrp with cyanogen maybe... But I want that only as a last resort because of the slim chances of me being able to flash a totally different ROM but not the stock one lol

Thanks for any help you can offer

 

[El Presidente]

Which flash tool are you using? The official one from LG or LGUP?

 

[musmula]

This one: http://lgflashtool.com

 

[El Presidente]

Ah, ok. Try this one - http://forum.xda-developers.com/tmobile-g4/development/stock-h811-20i-images-kdz-flashable-t3308227

There are links for a kdz file there and a link to the lgup tool.

The LGUP thread should also contain drivers which allow you to connect the phone to the PC in a way which allows LGUP to recognise it.

BTW, flashing something with a kdz file wipes the phone and installs an updated version of the OS from scratch, are you ok with that?

 

[musmula]

Sure

Gonna try that tonight, I'll let you know how it went

 

[El Presidente]

Great.

Make sure you read the instructions fully before hand.

LGUP is pretty straightforward, but it's wise to know what you're doing before hand.

Hope this gets you sorted!

 

[musmula]

Sorry for not getting back to you so long, I fell ill for a week and in that period my brain felt like it was cooked and the only thing it could manage is 1991 Picard

I took a swing at LGUP today and... Oh... Well... It recognises my phone as 'unknown' that is to say it doesn't recognise it at all... But all is not lost, eh? There is a notice in that xda thread about that specific problem and the solution is a file edit but there's a notice on that too: this fix requires root privileges... OK, whatever I'll just root the damn thing, not my first time rooting an android phone. Except I tried that a couple of weeks ago with kingo root and it failed... Twice

But okay, I'll just follow the super simple network of xda videos and threads on how to root the phone... Until it says: put this file right there via mtp... Dayumn that hurts

I guess I can somehow get that file over on my phone some other way, but not tonight

 

[musmula]

So I didn't do any of that. I found someone online who had the same problem with the LGUP tool and solved it by switching the ports assigned to the phone in the device manager. So I did the same: I changed the port for my phone from com5 or something to com46 or something, I don't remember correctly, needless to say tho I made sure I chose the right ports, I just don't remember now because I never thought I'll write this message the way I'm writing it now because after doing that, I fired up lg bridge and it recognized my phone and its specifications and it allowed me to update it and the update made it. It said it was successful and yet I can't turn on my phone!!!

I'm kinda loosing it here, what do I do? Everything went peachy until I was supposed to see results. I can't get it the download mode, I can't turn it on... If I connect it to a pc I just hear a chime and nothing happens. If I search the device manager I do see that a Qualocomm HS-USB QDLoader 9008 shows up on port COM6 but that's all. The phone doesn't give away ANY signs of life.

Oh boy, did I just irreversibly brick my only phone?