[HELP] [Q] Soft brick or hard brick? topic

I've searched around the forum and haven't hit a solution, so sorry if it's out there.

So, I have a Galaxy S4 Active (i537) ATT. I was given to me in a bootlooping state, and if I fix it I can keep the device.
What I have done to the moment:
Flashed every stock rom found in the forum with Odin (No luck on the device booting)

What the device does:
It shows the samsung splash, and restarts over and over, sometimes it doesn't even manage to get to the samsung splash.

Info on Download mode:
Product name: SGH-i537
Current Binary: Samsung official
System Status: Official
Knox kernel lock: 0xfffffffc
Knox kernel warranty void: 0xfffffffc
CSB-CONFIG-LSB: 0x30
Write protection: enable
emmc burst mode enabled

I'm new to samsung devices, so I hope someone can help me out here.

Thanks in advanced!