[AC Question]

Introduction and my phone's problems (you can skip it):
I bought a used Nexus 5X in the EU a month or so ago - it used to reboot every few minutes or on some ROMs 3 times a day, sometimes with bootloops and after some time visual artifacts started to appear when it froze, most of the time it didn't even reboot itself, I had to perform hard resets. I've tried it with different ROMs and the problem persisted even after flashing a factory image. Now it's worse - the phone won't turn on. When it starts to boot Android, horizontal colorful lines appear on the boot animation and it freezes and then loops the boot. I can get to the recovery and bootloader screens though. The phone is unlocked. I got it only with a micro-USB charger with an adapter. Nothing else. And I've checked the IMEI for theft, BTW.

As I've found out from the IMEI (by taking the back off), the phone isn't even a year old - produced at 2015-10-27, so I wanted to ask LG for a replacement, as this must be a hardware issue. And it looks like it's from France - "FR3 GOOGLE_OPEN_32G".
I have a few questions though:
1. Should I say that I bought it from someone or that I bought it in France or got it as a gift etc.?
2. Should I say that the bootloader is unlocked if they ask or should I lock it? (It has the orange Google warning.)
3. As I don't even have the bill of sale, should I say that I threw out or lost the documents? Can I even get it repaired without it? Is there a point in lying?
4. Should I disassemble and assemble it before sending it (if possible) for warranty? The motherboard could potentially have something not connected properly, but I think it's very unlikely.
If nothing works out, I'll either buy a used motherboard or sell it the way it is and just buy a SGS 5. I'm disappointed with the quality of N5Xs.
Thanks for reading.

[Rukbat]

1. Don't take it apart - that voids any warranty. (And lock the bootloader.)

2. Tell the truth. Either they'll fix it or replace it - or they won't. If they find out you're making up stories, they won't deal with you.

You bought a non-working phone - I wouldn't hold out too much hope for LG fixing it.

[B. Diddy]

Welcome to Android Central! Also, I don't believe the warranty is transferable. It's only valid for the original owner.