Return (almost) bricked phone to warranty

[BooBoss]

Hello guys,

I have a problem with my LG G3. Some time ago I bought for my phone a one way ticket to concrete floor trip. It seems he doesn't like it because digitizer was all cracked after the trip. I've replaced whole front of the phone (front case with factory installed screen and digitizer) - original LG part. Phone was working perfectly fine for about 2 months. One day I couldn't turn on screen - solution put off battery. Few minutes later after restart - same.... screen goes black. Eventually phone started to rebooting itself every few minutes.

Now - I have no idea if this behaviour has something to do with my recent screen replacement. If so - do you guys have any idea what loose parts or other mounting issues could do that?

Other option is - return it to warranty repair. I think that they shouldn't notice I've replaced front by myself. Part is geniue LG and rather well replaced. BUT.... (there's always some "but") there's another problem - I have custom ROM, custom recovery and root of course ;-) I can't send a phone in this state. But again I cannot reverse it's state to stock because it's restarting or hanging all the time.

So the real question is: how can I soft brick or hard brick the phone so no one will notice what software is actually installed there and just replace mainboard?

Some time ago I had Samsung S3 which suddenly powered off and didn't come back to life again. Warranty repair was no problem because there was absolutelly no way to see what firmware and generally software is installed there. Now I wan't to do something simillar with my G3 so I can send it to warranty. But question is how?

 

[amitd44]

Flash Original Firmware and Lock bootloader again on Fastboot mode (code: fastboot oem lock). No one can tress it for root, custom ROM. so, you will free for tension.
(Note: Bootloader lock code may be change as per device manufacturer).

 

[BooBoss]

Flash Original Firmware and Lock bootloader again on Fastboot mode (code: fastboot oem lock). No one can tress it for root, custom ROM. so, you will free for tension.
(Note: Bootloader lock code may be change as per device manufacturer).

Thank you for you reply but the point is I can't do it because phone is restarting every few minutes. I won't have enough time to finish flash operation and if the phone restarts again during flash there might be a problem.