@toto1988 - OK. I managed un-bricking my device finally.
Basically, the main tutorials I was using were:
1.
https://forum.xda-developers.com/le-2/help/bricked-le-s3-x626-flashing-twrp-power-t3715937
2.
https://www.youtube.com/watch?v=8wlnJOKISDM
I, like you was stuck at the same phase of trying to flash the phone. What I did, which solved it, was to change the DA_PL_HIGH.bin into the DA_BR.bin file (this file should have been used later on, and all the guides I saw specified the DA_PL_HIGH and not the DA_BR, but none of them mentioned the 0xC0060003 error). I was desperate, and had nothing to lose, so I tried various bin files till I got to the DA_BR which worked for me.
Now, I'm continuing with the tutorial to flash a good ROM (which won't be mirroring my screen).
Please take into consideration that I did it out of desperation, and I'm not responsible for any damage it might cause to your device. If you want to try it - do it on your own risk.
Maybe it's better you'll wait for other more expert guys than me which might reply on what I tried to either confirm or warn you about this method.
Hope it'll help you.
Thanks,
Tamir
