Default [Q] Sprint Toroplus - Infinite Boot

Hello,

Will try to explain the best I can. So I was using my GNex (sprint variant) which I had freshly unrooted and flashed back to 4.2.1 stock (then it OTA updated itself to 4.3). In hindsight, I realized that I forgot to lock it after unrooting it. Not sure if this contributed to the problem, but I figured it would be best for you guys to know.

I was using the phone last night, and the screen started to flicker, and eventually the phone shut off. It would not boot for the longest time. I plugged it into a wall and attempted to start up which it did, only to go directly into power shutdown (it said the battery was low). In addition to this, the screen was flickering and the screen eventually cut out.

This lead me to believe I had done something wrong in going back to stock-- when I boot the phone in recovery mode, there is no screen flickering, and the apparent low battery doesn't seem to be an issue.

I attempted to flash 4.2.1 using WugFresh's Nexus Root Kit-- Everything was a success until it notified me that the baseband was inappropriate for 4.2.1. My current baseband is L.700 GJ04 which I never updated myself-- so I can only assume this came from the OTA 4.3 update from Sprint. It notified me that it needed the GA02 radios, which I attempted to install via fastboot. The cmd prompt said the installs were successful for both the CDMA and LTE .img files, but on the bootloader screen, the device still reads as having the GJ04 radios.

When I attempt to start the device, it boots infinitely with the Google screen. Any thoughts on how to proceed? I can't find a factory image of the 4.3 update-- Would this fix this?

My apologies for sounding uneducated at some points. It's become apparent to me you can't half-ass tweaking with your phone's DNA...