So I'm kinda a newbie to flashing ROMs I just got a galaxy s4 back in November and the official kit kat update killed my expirence with the s4 so I got a refurbished s4 with mk2 baseband and from what I've read the bootloader was locked. I'm on sprint but I've been flashing away like no tomorrow and yes I've been making nandroid backups and everything incase something goes wrong. (I've soft bricked my phone 4 times) but I'm just curious on how to get back to my stock mk2 rom? I've tried restoring my backup from twrp and can't get it to boot it just get stuck in a bootloop. Any help would be really nice.