My issues is quite complicated. Please be patient and read on.
Less than a week ago, I bought an LG G3 D855. It wasn't brand new and definitely out of warranty.

It was on the 4.4.2 Os version but I couldn't update it because I couldn't locate the UPDATE CENTER and after some research online, I found out it was because it was rooted. I couldn't find a Supersu application anywhere on the phone anyways but Root checker confirmed that it was rooted.
I downloaded the stock kitkat firmware in a .tot format and I tried flashing using LG Flash Tool for TOT but it failed because "Device version is different"
I checked the Imei online and it stated that the device is a Sprint LS990 but the details embedded in the phone all say it is D855

I checked online and found a couple of posts about this error and one user said he was able to fix it by flashing the actual Sprint .tot with the lg flash tool. I tried that but it didn't work. It still said "Device version is different. Check BIN or dll"

I checked online and found results pointing to a generic .dll file for G3s and I downloaded it but when I used it on the Flash tool, it resulted to an error "CrossDL blah blah"

So I found a Marshmallow kdz file. LGUP won't see my device model so I was able to flash it after editting the software in my build.prop to D85510n.

***I have always changed the port to COM41 in all the steps I used

The LG UP detected my model and it flashed to 100% but got stuck on a bootloop by loading the lg screen, freezing and restarting by it self. It never gets to the homescreen.
I downloaded lollipop kdz reflashed using LGUP in a form of downgrade and it got to 100% and got stuck at the lg screen while trying to reboot.

I redownloaded the stock kitkat rom and used the Lg flash tool but it failed. It said 'PID null IMEI Null"

I used LGUP to reflashed. It came to my understanding that the LGUP can flash both kdz and tot. So it flashed to 100% but got stuck at the lg screen and I have tried all I can but it is stuck. It can go into download tho. I don't know what to do about the IMEI. I don't know if the last flash retrieved it. I don't kniw what to do.

It no longer shows as LGE AndroidNet USB Serial

Please can anyone help me?
I just need my phone to work again. I was stubborn and now I regret it. I should have just stuck to kitkat. I'm so desperate to get my phone working that I wouldn't mind Android Froyo Os if it was ever possible.
PLEASE HELP!!!

Case seems complex
Whatsapp me 07032443577 if u r in lagos


I think if u can get the name of the custom rom that was On it, boot into recovery and flash in that particular rom

Wow! Seems you actually know your way around flashing phones and stuff.

By your explanation I think flashing a stock Sprint rom is the only way to get the device working again. Remember that it's firmware is embedded with Sprint properties therefore flashing anything other than their rom is gonna affect it.

P.S. When next you get a branded phone, try not to get too eager for updates coz that's their major drawback. Hope you fix it soonest

unrelated but needed to ask, have a tmobile lg g2d801, not rooted and its being prompting me to update. there's no way to get rid of the prompt, is there any risk if i update as that seem to be the only way to get rid of it.

t33why:
unrelated but needed to ask, have a tmobile lg g2d801, not rooted and its being prompting me to update. there's no way to get rid of the prompt, is there any risk if i update as that seem to be the only way to get rid of it.

If u r 101% sure yr phone isn't rooted and has never been rooted, u can install

Try to disable auto download in ur software area on d phone