I have Verizon's Galaxy S3 and had CyanogenMod 10.2 installed on it. After installing CM 10.2, I no longer had 4G/3G connection. After some research, I had discovered that it had to do with my device's APN. Anyways, what I found online was to unroot, and flash to a stock ROM, and wipe/reset factory settings, etc.
I started by flashing a stock ROM found on this site (don't remember the name) however, after rebooting, my phone had gotten stuck in the white Verizon logo loop. After pulling the battery, I tried flashing the image again in ODIN, but the same thing happened, I figured this is what was known as a "soft brick". I followed another guide on here to unroot/unbrick the phone, which had me download another stock rom (stock.vzw_root66), as well as VRALEC.bootchain.tar.md5, and BOOTLOADER-I535VRALF2-618049-REV09-user-low-ship.tar-2-.md5. Following the instructions had me PDA flash the VRALEC-bootchain.tar.md5 first, followed by the bootloader, and finally the stock image. However, I continued to get "FAIL!" after attempting to flash the VRALEC-bootchain.tar.md5.
Following another guide, it said to just try flashing the stock.vzw_root66 file, which I had done, and it succeeded, however, after the phone reboots, it says that I am using unauthorized firmware on my device, and to bring my phone to the nearest Verizon store.
Now, I have no idea what to do.
I'm using ODIN3 v3.07
Both the VRLEC.bootchain.tar.md5 and BOOTLOADER-I535VRALF2-618049-REV09-user-low-ship.tar-2-.md5 fails when trying to flash them onto my phone, and I don't want to proceed from here unless I know how to fix it, as to not damage the phone any further. Any help would be greatly appreciated!
The phone still boots into a stock recovery, and can still enter download mode. At this point, I just want my phone completely stock, as if I had just purchased it.