LG G3 bit rot

Lineage is a very good solution, as there's still actively work done on it. If your phone crashes due to hardware issues, obviously you will never get a stable phone back.

First make sure exactly which LG G3 version you have. If it's for instance, the unlocked international version, all info is on this page:

https://wiki.lineageos.org/devices/d855

Strangely enough i'm doing that right now. I'm in TWRP and trying to find the exact version and wondering how ..?

Sorry - ignore - it's d855

OK that exercise failed. I can't install the latest Lineage on it. I'm now without an OS but can boot into TWRP

What happened exactly? Was there an error, before install? During install? After install?

After install. Also tried to install stock firmware with TWRP. Nothing's working. I suspect a hardware error now

Don't forget it's good practice to use the TWRP's  Advanced Wipe functions before installing a new OS (Data, Dalvik Cache, System and Cache)
Obviously a hardware defect could very well be possible (if it ran ok, then started failing without you really changing the OS that much)

This time i've done a repair on partitions that look important. I'm going to go ahead and TWRP install the stock Marshmallow firmware, zipped. The last time i tried this it appeared to be fine but never got beyond the LG logo at boot

Again it all appeared to be fine. But this time when i pressed reboot it told me there was no OS installed and was i sure i wanted to!

I paid 75GBP for this, rooted. I've just seen one for c. 15GBP so i might get it as at least i've already got spares ;)

I'll need to root it myself then of course

Oops, it's an Ebay auction, not buy-it-now ;)

If you go through 3 of those in 3 years, you've had a slow phone for 3 years (and three times the bothersome switching, backup/restore etc), compared to the same price where you would have a brand new one that's faster that might not need the regular change in those years.
All worst case speculation, of course.

Oh they're certainly fast enough for me. I just don't want them dying. They are used though when i buy them

LG G3 has a design fault which make it unusable.

https://forums.androidcentral.com/lg-g3/778802-bootlooping-lawsuit-why-isnt-g3-included.html

The same problem appears on many models of LG android phones and there is a class action lawsuit against LG.

https://www.xda-developers.com/lg-bootloop-lawsuit-settlement-backtrack/

Stay away from LG android phones if you will get a new one.

If you need to buy a used phone again, select flagship models of Samsung and buy it via Craigslist or other similar forums and test it before you trade.

Thanks for letting me know. I wonder why it's just appeared after months of use? And i wonder if it counts as a bootloop?

I wonder why it's just appeared after months of use? And i wonder if it counts as a bootloop?

It is a manufacturing defect and only the insiders of LG knows about the real cause.

Besides, your symptoms suggest it is a bootloop as your motherboard seems to be OK but it cannot properly access the storage.

You can also say it wear and tear problem that the storage just loose contact to the mainboard of the phone after an uncertain period of time. Without the storage, the phone is just a brick and there is no practical mean to repair it.

Thanks folks. I'm going to sell this for parts and get a rooted Samsung from Ebay