[Q] GS5 (SM-G900A) Hanging During Boot topic

Device: AT&T Galaxy S5 OS 4.4.2 (carrier locked)
Background: Applied AT&T OTA 4.4.4 update (device showed it available from AT&T), once update finished applying the device couldn't connect to AT&T mobile data (WiFi worked and incoming/outgoing calls worked). I tried several different troubleshooting methods and ended up doing a factory reset. This didn't resolve issues. So I tried flashing the ROM; this is where things took a massive turn south.

Issue: Device boots to Samsung logo and hangs (logo partially loads before hanging). I can get to recovery and to download mode for Odin. I've used the following guides for flashing: (I don't have enough posts to set links so I posed them below)

• galaxys5root(.)com - Downloaded flashing files and Odin twice to ensure no issues. Got the same result flashing all of these. I couldn't flash blootloader, I assume because it is still locked.


• galaxys5update(.)com - I used this guide with files from sammobile(.)com for "AP" on Odin. I'm currently downloading the files hosted on GalaxyS5Update's guide, but I still have another few hours before they finish.

This isn't my first go around with flashing ROMs on Android, however it is my first try with locked Samsung phones (I've always used Nexus devices prior to this).
I'm at a loss where go go from here. I'm not sure exactly what I'm doing wrong nor am I sure where to look to move forward.

I appreciate any help anyone can provide. Let me know if I didn't provide enough information or wasn't clear enough.

Thanks!
J



Just in case the links don't work:
Guide 1 - galaxys5root(.)com/galaxy-s5-unroot/how-to-unroot-galaxy-s5-with-odin-and-stock-firmware/
Guide 2 - galaxys5update(.)com/unbrick-att-galaxy-s5-sm-g900a-soft-brick-fix-restore-to-stock-firmware/
SamMobile - sammobile(.)com/firmwares/download/28224/G900AUCU1ANCE_G900AATT1ANCE_ATT/