hey idk if this question has already been answered or what? but i happen to have two galaxy s3's, one being my daily driver from VM and one being a t-mobile varient that i happen to have gotten for free. i use the t-mobile one to test roms before using my VM since i need full functionality.
i recently tried to flash the 4.4.3 D-Unicorn rom with all the correct T-Mobile accents available to my knowledge and its now hrd bricked to the max. no life what-so-ever.
but really my question is weather or not everything here can be used for a person coming from 4.3 on VM? im scared to try it on my VM version since my TM version just got destroyed trying it.
do i need the ND8 or NDC bootloader? i think i have the MK5 modem now. i read the description but still need clearification.
You don't need ND8, NDC, or MK5 bootloader to make these ROMs work. I have MD7 on my phone and I've used all of these ROMs. I'm currently using Dirty Unicorns 4.4.3.
My phone came with 4.1.2 preinstalled on it. But yes, you can use these ROMs if your phone had 4.3 preinstalled. Just be careful because of Knox. It can muck things up fast. I think your problem might've been flashing the modem, but I don't know. You don't need to flash it if you have MK5 modem. You only really need to flash it if you had 4.1.2 preinstalled on your GS3.
These ROMs are all d2lte ROMs, meaning they work on any version of GS3. At first, ROMs were made for specific versions of GS3 depending on what carrier they were on. Now, ROMs for GS3 are made to work for all versions of GS3 of all carriers. So, the same ROM you downloaded to use on the Virgin Mobile GS3 will work on the T-Mobile GS3 without needing any special treatment. It could've been the special accents you used that caused the phone to brick also.
You shouldn't need to flash the APN settings fix if you flash a d2lte ROM with your T-Mobile phone (I guess that's moot because it is now bricked). That's only necessary for us on Virgin Mobile because even though our phone is the same as the Sprint version, ours uses different modems. Ok, so technically, a d2lte ROM is made to be used on any Sprint, T-Mobile, Verizon, or AT&T GS3 phone. But it works with us also. Because of the modem difference with ours and Sprint GS3 phones, we need to flash the APN settings fix to get our data up and running.
Since your phone came with 4.3 and has MK5, you should be able to flash the d2lte ROM, 4.4.3 GAPPS, the APN settings fix and it should be good to go. If you get your T-Mobile GS3 running again, all you'd need to do is flash a d2lte ROM and 4.4.3 GAPPS. I hope this answers some of your questions.