Database Users

[Q] Questions about FW updates on my S4..

I'm used to my Skyrocket so I'm not too noobish, but the s4 is different so I want to do this right.
So I have been reading Haphim's thread listed below about getting his new phone and he said it came with the MDL fw.
http://forum.xda-developers.com/showthread.php?t=2432816
Mine came with MDB FW. I immediately turned off the OTA updates after I rooted the phone. I had some issues trying to rename the Data Management app, so I used TBU to freeze it. Thank goodness ~wolverine~ posted a link to the 3 updates I needed to freeze. I found 2 of the 3 updates, but FWUpgrade x.x.x was not listed on my device. Is this because of the age of my firmware? This was NEW in the box, so I must have gotten one that had been sitting on a shelf somewhere, that is if the MDB fw is older..
Now if the above holds true about the MDB FW, are there any advantages of this one over any others?
What about modems? Can I update to a newer modem without upgrading my FW?
I'd like to go to a newer TW based rom (I have a Samsung TV and would prefer to use Allshare, ect). Can I do this with just flashing the rom via TWRP? Do I need a newer modem to do so? I saw some mention that an international version of TW rom is better. Why would that be? I'd like to jump to 4.3, but I'm still on 4.2.2.
Just a side question, does the CM based roms have Bluetooth issues? the Skyrocket CM based roms had connectivity issues where you'd have to reboot to get BT functionality back.
Sorry for the list of questions, I just got this phone and do not want to brick it.

I'm assuming you already found this, but if not it's a good place to start. http://forum.xda-developers.com/showthread.php?p=42320391
Flashing roms is not as straight forward as the sr as the boot loader is locked and you need to use Loki to work around it. If it were mine I'd Odin to mdl, root it and freeze the update apps so you don't get mf3. Then do more research until you're comfortable flashing.

Thanks for the reply. The thread you linked was very informative.. but..
What about the other questions? Modems, CM issues, ect?

[Q] Upgrade to MK6 modem?

Ok, I'll start by saying that I'm trying to update my rogers 1337m to a custom ROM based on 4.4. The phone came with 4.2.2 on it and the 1337MVLUAMDJ modem. Since having bought it, I rooted it with motochopper, kicked the samsung firmware to the curb, and installed jamal's 4.2.2 google edition rom.
Anyhoo, now I want to install jamal's 4.4 rom. I installed it, but the phone doesn't work. I can't make calls, mobile data isn't working, and I get no bars in the signal indicator. I restored my nandroid backup to 4.2.2 and all is well again - calls, mobile data, and signal reception.
Do I need to upgrade my modem firmware? I have the MDJ firmware, and I noticed that there's an MK6 firmware that seems to be newer. Jamal's rom actually comes with a modem, I9505XXUFNA1, but when I tried installing that with Odin, it said 'security check failed'. I'm guessing that I can only install Canadian modems?
What would be the pros/cons of flashing MK6? Does this unroot my phone? Does this lock my boot loader? I seem to recall that AT&T pushed out an update that locked their users' phones in some way. Is that what I would be in for?

tedmm said:
Ok, I'll start by saying that I'm trying to update my rogers 1337m to a custom ROM based on 4.4. The phone came with 4.2.2 on it and the 1337MVLUAMDJ modem. Since having bought it, I rooted it with motochopper, kicked the samsung firmware to the curb, and installed jamal's 4.2.2 google edition rom.
Anyhoo, now I want to install jamal's 4.4 rom. I installed it, but the phone doesn't work. I can't make calls, mobile data isn't working, and I get no bars in the signal indicator. I restored my nandroid backup to 4.2.2 and all is well again - calls, mobile data, and signal reception.
Do I need to upgrade my modem firmware? I have the MDJ firmware, and I noticed that there's an MK6 firmware that seems to be newer. Jamal's rom actually comes with a modem, I9505XXUFNA1, but when I tried installing that with Odin, it said 'security check failed'. I'm guessing that I can only install Canadian modems?
What would be the pros/cons of flashing MK6? Does this unroot my phone? Does this lock my boot loader? I seem to recall that AT&T pushed out an update that locked their users' phones in some way. Is that what I would be in for?
Click to expand...
Click to collapse
The i337m will never have a locked bootloader. AT&T was never unlocked, we only had an exploit. Updating yours will get you Knox however, i believe. There is a thread of the modems so you can flash just the modem by itself.

DeadlySin9 said:
The i337m will never have a locked bootloader. AT&T was never unlocked, we only had an exploit. Updating yours will get you Knox however, i believe. There is a thread of the modems so you can flash just the modem by itself.
Click to expand...
Click to collapse
I've seen knox before in my process list - when I had the samsung firmware installed, I thought knox was just an obnoxious ( obknoxious? ) policy agent for enforcing exchange rules or something. I've seen neither hide nor hair of it since I installed the google edition ROM, which of course doesn't come with knox. So you're saying the the new modem might have some knox component in it and this might cause problems?

tedmm said:
I've seen knox before in my process list - when I had the samsung firmware installed, I thought knox was just an obnoxious ( obknoxious? ) policy agent for enforcing exchange rules or something. I've seen neither hide nor hair of it since I installed the google edition ROM, which of course doesn't come with knox. So you're saying the the new modem might have some knox component in it and this might cause problems?
Click to expand...
Click to collapse
Well if you already had a version with knox it doesn't make a difference. It's just that the newer official firmwares have the knox enabled bootloader and it adds an extra flag beyond the normal system status that would void your warranty on flashes but if you already have it then it doesn't matter. It wouldn't cause any problems, just adds that little flag and I'm not sure if recoveries are made to not trip that flag or what.

tedmm said:
I've seen knox before in my process list - when I had the samsung firmware installed, I thought knox was just an obnoxious ( obknoxious? ) policy agent for enforcing exchange rules or something. I've seen neither hide nor hair of it since I installed the google edition ROM, which of course doesn't come with knox. So you're saying the the new modem might have some knox component in it and this might cause problems?
Click to expand...
Click to collapse
As far as I know, Knox is not part of any modem firmware. Someone please correct me if I'm wrong.
Sent from my SGH-I337 using XDA Premium 4 mobile app

TLK3 said:
As far as I know, Knox is not part of any modem firmware. Someone please correct me if I'm wrong.
Sent from my SGH-I337 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
It isn't, flashing only the modem packages does not include knox. Using the full system ODIN or Heimdall files will include it if you update the bootloader.

tedmm said:
Ok, I'll start by saying that I'm trying to update my rogers 1337m to a custom ROM based on 4.4. The phone came with 4.2.2 on it and the 1337MVLUAMDJ modem. Since having bought it, I rooted it with motochopper, kicked the samsung firmware to the curb, and installed jamal's 4.2.2 google edition rom.
Anyhoo, now I want to install jamal's 4.4 rom. I installed it, but the phone doesn't work. I can't make calls, mobile data isn't working, and I get no bars in the signal indicator. I restored my nandroid backup to 4.2.2 and all is well again - calls, mobile data, and signal reception.
Do I need to upgrade my modem firmware? I have the MDJ firmware, and I noticed that there's an MK6 firmware that seems to be newer. Jamal's rom actually comes with a modem, I9505XXUFNA1, but when I tried installing that with Odin, it said 'security check failed'. I'm guessing that I can only install Canadian modems?
What would be the pros/cons of flashing MK6? Does this unroot my phone? Does this lock my boot loader? I seem to recall that AT&T pushed out an update that locked their users' phones in some way. Is that what I would be in for?
Click to expand...
Click to collapse
were you able to figure this out?

Faultyy said:
were you able to figure this out?
Click to expand...
Click to collapse
Yes.
First, I don't think that it was strictly necessary to upgrade the modem to get 4.4 - I think it might have just been a problem with jamal's ROM and the kernel he used. Anyways, I decided that I wanted the new modem anyways because I reasoned that it would probably have bug fixes and performance and reception improvements. I was pretty sure that flashing the official 4.3 Rogers image (there is no 4.4 Rogers image) with Odin would give me the new modem. Then I could flash whatever aftermarket ROM I wanted.
Strangely, this didn't work. At least not the way using Odin is recommended. Odin has two text fields pointing to tar.md5 Roms - onw of them is marked 'phone' and the other is marked 'PDA'. As I recall, I had to point BOTH of these at the official Rogers 4.3 ROM get get both the Samsung/Rogers android along with the Qualcomm mk6 modem. I don't think I've ever found a how to where they recommend using both at the same time.
After that, I flashed a Google edition ROM and all is well. And the new modem does seem to get somewhat better reception.

So there is no way to update just the modem from a custom ROM (without wiping everything and installing a stock ROM) for Canadian S4s?

[Q] Some fairly Noob Clarifications (TWRP/CWM/MDL Related)

Purchased my S4 at launch, only rooted it and never really got around to tweaking it much. It has slowed down a bit so now is the time.
I'm on MDL, stock 4.2.2, and rooted with TWRP 2.5.0.2 On to the questions/clarifications, hopefully these aren't egregious. I know the info is out there but for actually finding specific information, the xda forums are a bit overwhelming and sometimes conflicting...
1) Recovery - Latest/preferred recovery for the s4 (on MDL) with auto-loki baked in? Are any of the latest versions of TWRP/CWM dangerous/incompatible or can I just install the latest/greatest with ROM Installers and go from there?
2) Modem - Flashing an updated modem, regardless of ROM/OS # should not break anything and/or lock down the bootloader any more so than it already is at MDL, correct? Updating the baseband will have no effect on the build # and thus loki is still and option (versus safestrap)? Preferred modem at this time? (ATT, SF Bay Area)
3) ROMS - Any ROM, followed by loki patch or flashed via an auto-loki capable recovery should be fine, correct? Is a ROM specifically built for safestrap applications and thus would not work with MDL, or are ROMs noted as being safestrap ready just able to be used via safestrap, but loki as well?
4) Hard to keep track of all the ROMs and the builds and branches etc - Can anyone point me in the right direction of either a) the latest stock touch-wiz 4.4.4 ROM that can be flashed over MDL without essentially updating past MDL? b) the best/most recent pure google (Play Store S4 Edition) ROM, same story with not breaking MDL?
Again, I apologize I am sure the info is all buried in here somewhere, it just gets to a point where pointed questions rather than multiple 500+ post threads are hopefully less likely to brick my phone. Ideally I just want to get on the latest software (and enable screen casting, for one). Assuming it comes quick enough, once I get this process down I will probably make the jump to 5.0 when it is ready, anticipate a couple months? Who knows.
Thanks, much appreciated.

Norcalz71 said:
Purchased my S4 at launch, only rooted it and never really got around to tweaking it much. It has slowed down a bit so now is the time.
I'm on MDL, stock 4.2.2, and rooted with TWRP 2.5.0.2 On to the questions/clarifications, hopefully these aren't egregious. I know the info is out there but for actually finding specific information, the xda forums are a bit overwhelming and sometimes conflicting...
1) Recovery - Latest/preferred recovery for the s4 (on MDL) with auto-loki baked in? Are any of the latest versions of TWRP/CWM dangerous/incompatible or can I just install the latest/greatest with ROM Installers and go from there?
2) Modem - Flashing an updated modem, regardless of ROM/OS # should not break anything and/or lock down the bootloader any more so than it already is at MDL, correct? Updating the baseband will have no effect on the build # and thus loki is still and option (versus safestrap)? Preferred modem at this time? (ATT, SF Bay Area)
3) ROMS - Any ROM, followed by loki patch or flashed via an auto-loki capable recovery should be fine, correct? Is a ROM specifically built for safestrap applications and thus would not work with MDL, or are ROMs noted as being safestrap ready just able to be used via safestrap, but loki as well?
4) Hard to keep track of all the ROMs and the builds and branches etc - Can anyone point me in the right direction of either a) the latest stock touch-wiz 4.4.4 ROM that can be flashed over MDL without essentially updating past MDL? b) the best/most recent pure google (Play Store S4 Edition) ROM, same story with not breaking MDL?
Again, I apologize I am sure the info is all buried in here somewhere, it just gets to a point where pointed questions rather than multiple 500+ post threads are hopefully less likely to brick my phone. Ideally I just want to get on the latest software (and enable screen casting, for one). Assuming it comes quick enough, once I get this process down I will probably make the jump to 5.0 when it is ready, anticipate a couple months? Who knows.
Thanks, much appreciated.
Click to expand...
Click to collapse
I will try to help with a few of these questions, but others I am not familiar with very much. On that note DO NOT update your bootloader!!! It will be locked down further and Loki will NOT WORK. And you could NOT flash any kernels with safestrap. So with safestrap ONLY the stock kernel can be used. Now on to your questions...
1) I am using TWRP 8.1 if I remember correctly. You can find it in the Original Android Development section. It does NOT Auto Loki, so keep the loki-doki flashable zip on your sdcard OR use Roms that already have/use the boot.Loki kernels like ShoStock-i 8.1
2) Modem flashing will NOT lock anything up further as far as the bootloader. You can flash ANY or ALL of them from my modem thread. See which works BEST FOR YOU in YOUR AREA. I am in So Cal and the best for me has been either MDL. But I have and do test ALL of them. You can always flash back to whichever one works best for you.
3.) Like I said I use ShoStock-i 8.1 because it has and does EVERYTHING I need my phone to do and does it without any issues. I have NOT tried to use a Safestrap modified ROM so I have very little experience with that. Normally most devs will have two separate versions, one for safestrap compatible and one for us without safestrap. ShoStock-i is already built with Loki in the kernel so you do not NEED to flash Loki-Doki patch.
4) there are NO Touchwiz 4.4.4 Stock Roms for ATT yet. But I did try out one of the Touchwiz 4.4.4 T-Mobile based Roms and it worked perfectly. You can either get it from the ATT forums and I believe it is already lokified, or get it from the T-Mobile forum and make sure to flash Loki-Doki patch before booting up phone after flashing the ROM. Again the will NOT update your bootloader past your MDL bootloader, so you are good as you are with no worries. By the way on ShoStock-i 8.1 the screen casting to Chromecast works PERFECTLY without having to flash any other .apk's or mess with ANYTHING

This is the exact same boat I'm in. Trying to track down the answers as well. Will keep an eye here as well to watch for answers.

awesome reply thanks RockRatt, that just about covers it. I will maybe give the ShoStock ROM a go and see how I like it. As long as all the normal features are working fine, I should be good.
One last thing I forgot - Odin. I have the stock odin firmware files from when my phone was new (The MDL package). As long as I dont update the bootloader, I should be able to Odin back to the brand new in box state should something go awry or not dig the other ROMs, correct?
Thanks again,

Norcalz71 said:
awesome reply thanks RockRatt, that just about covers it. I will maybe give the ShoStock ROM a go and see how I like it. As long as all the normal features are working fine, I should be good.
One last thing I forgot - Odin. I have the stock odin firmware files from when my phone was new (The MDL package). As long as I dont update the bootloader, I should be able to Odin back to the brand new in box state should something go awry or not dig the other ROMs, correct?
Thanks again,
Click to expand...
Click to collapse
Yep. Just don't update the bootloader...So no flashing newer firmware that contains the bootloader files. Most if not all custom Roms do not have the bootloader files in them. So no problem flashing back to MDL stock if the need never arises. I still in fact have the original MDB bootloader installed that came with the phone before the MDL firmware update.

New around here. Some doubts.

Hello.
Ever since I bought a Galaxy Nexus and found XDA, my life changed. Without noticing I got infected a virus: addiction to Android.
My Nexus got outdated quickly and now is pretty done and I need a new toy. 3,5 years later I finally got some spare money to buy a new phone. Since here in Portugal the minimum wage is around 500€ and top flagship phones cost around 700€ (and there's no affordable contract to get something cheaper and still nice), I had to wait until now to get a used Note 3 for 300€.
I love the phone's design and above all the specs. There's no other phone with 3GB RAM and Snap 800 for this price and I always liked big sized phones.
Well, I write too much unnecessary info... I need to stop
Let's get down to the point. I will get the phone tomorrow!!
TL;DR
How do I check the bootloader version? I want to flash TWRP right away and maybe install a Note4/5 port or something stock Android, do I need to be careful with the bootloader?
I know from other phones (i.e LG G2) that any custom rom uses KK bootloader and the stock roms use their respective version bootloader. Is this also true for the Note?
Also, which version of TWRP should I flash? Does it depend on the stock rom version that I have?
Checking if the device has 2.3x GB of available RAM, if Odin and Recovery have their stock aspect and if the S-Pen works is enough to ensure that the Note I'm getting is truly original?
Well, that's all. I'm sorry if I'm asking the same questions everyone does. I'm used to Nexus so I'm afraid of bricking the Note with dumb moves. That's why I am taking my time to read every important thread and asking here some doubts that went into my mind while doing the required reading. I have no warranty (no box nor invoice) so I can't afford to mess up with the new babe
Cheers!

This app!
diogofd8 said:
Hello.
Ever since I bought a Galaxy Nexus and found XDA, my life changed. Without noticing I got infected a virus: addiction to Android.
My Nexus got outdated quickly and now is pretty done and I need a new toy. 3,5 years later I finally got some spare money to buy a new phone. Since here in Portugal the minimum wage is around 500€ and top flagship phones cost around 700€ (and there's no affordable contract to get something cheaper and still nice), I had to wait until now to get a used Note 3 for 300€.
I love the phone's design and above all the specs. There's no other phone with 3GB RAM and Snap 800 for this price and I always liked big sized phones.
Well, I write too much unnecessary info... I need to stop
Let's get down to the point. I will get the phone tomorrow!!
TL;DR
How do I check the bootloader version? I want to flash TWRP right away and maybe install a Note4/5 port or something stock Android, do I need to be careful with the bootloader?
I know from other phones (i.e LG G2) that any custom rom uses KK bootloader and the stock roms use their respective version bootloader. Is this also true for the Note?
Also, which version of TWRP should I flash? Does it depend on the stock rom version that I have?
Checking if the device has 2.3x GB of available RAM, if Odin and Recovery have their stock aspect and if the S-Pen works is enough to ensure that the Note I'm getting is truly original?
Well, that's all. I'm sorry if I'm asking the same questions everyone does. I'm used to Nexus so I'm afraid of bricking the Note with dumb moves. That's why I am taking my time to read every important thread and asking here some doubts that went into my mind while doing the required reading. I have no warranty (no box nor invoice) so I can't afford to mess up with the new babe
Cheers!
Click to expand...
Click to collapse
https://play.google.com/store/apps/details?id=org.vndnguyen.phoneinfo&hl=en
this app will help you confirm your phone.
then you can proceed flashing twrp and supersu, things are so easy for N9005
and Welcome Aboard

Install phone info samsung from playstore. It could tell a lot about your phone.
To make it easy as long as the phone is running with android version 4.4.2 and above you should use twrp 4.4. If 4.3 use the right one for 4.3.
Sent from my SM-G925F

White Note3 do you have? There are several versions made by Samsung.
Regardless of the bootloader on the phone, I recommend using the latest TWRP as the latest TWRP can be used to flash all ROMs and zip files. Find your device from here: https://twrp.me/Devices/
Before moving to custom ROMs, I also recommend installing the latest bootlloader and ROM.
Not sure if your phone still has warranty but if it does, I would not change the ROM or root because doing either may trip the knox counter and void the warranty.

nijom said:
https://play.google.com/store/apps/details?id=org.vndnguyen.phoneinfo&hl=en
this app will help you confirm your phone.
then you can proceed flashing twrp and supersu, things are so easy for N9005
and Welcome Aboard
Click to expand...
Click to collapse
Thanks! I will keep the link in my favorites and install the app when I get the chance to test things.
Rosli59564 said:
Install phone info samsung from playstore. It could tell a lot about your phone.
To make it easy as long as the phone is running with android version 4.4.2 and above you should use twrp 4.4. If 4.3 use the right one for 4.3.
Sent from my SM-G925F
Click to expand...
Click to collapse
Thanks! I'm pretty sure it has 4.4.x or lollipop. Should I update to any of those versions (just in case it comes with 4.3) first and then install TWRP?
audit13 said:
White Note3 do you have? There are several versions made by Samsung.
Regardless of the bootloader on the phone, I recommend using the latest TWRP as the latest TWRP can be used to flash all ROMs and zip files. Find your device from here: https://twrp.me/Devices/
Before moving to custom ROMs, I also recommend installing the latest bootlloader and ROM.
Not sure if your phone still has warranty but if it does, I would not change the ROM or root because doing either may trip the knox counter and void the warranty.
Click to expand...
Click to collapse
The phone doesn't come with box nor invoice so I don't have any warranty xd
What is the number or version of the latest bootloader?

What is the model # of the phone? There is the n-900t, n9005, n-900w8, etc.

N9005, it's the european unlocked version

The model # is important when asking questions because the AT&T version of the note 3 has a locked bootloader so it's more complicated to flash custom recovery and to get root.
If you want to run custom ROMs, I recommend upgrading to the latest modem and bootloader, install a custom recovery, back up your stock ROM, and try some custom ROMs to see which one you like.
Look for the tar version of TWRP for your phone from here: https://twrp.me/Devices/
You can flash TWRP with Odin.

audit13 said:
The model # is important when asking questions because the AT&T version of the note 3 has a locked bootloader so it's more complicated to flash custom recovery and to get root.
If you want to run custom ROMs, I recommend upgrading to the latest modem and bootloader, install a custom recovery, back up your stock ROM, and try some custom ROMs to see which one you like.
Look for the tar version of TWRP for your phone from here: https://twrp.me/Devices/
You can flash TWRP with Odin.
Click to expand...
Click to collapse
I'll get the phone tomorrow!!!!!
So, by upgrading to the latest official rom avaiable I'll have the most recent modem and bootloader, right?
Do I need to follow the order you mentioned: modem->bootloader->recovery->backup->croms or can I flash TWRP, backup every partition, flash most recent modem and bootloader (not sure if I can flash a bootloader) and then install croms?

No, only flashing a newer custom ROM won't update your Bootloader and Modem. You will need to flash those files separately via Odin. Then you can flash the custom ROM you want. The order is simple. Get a custom recovery first, TWRP. Then update your Modem and Bootloader. Then wipe the device from TWRP (full wipe, take backup beforehand if you need) and flash the custom ROM of your choice.

Safest way to upgrade the modem and bootloader is via ota update on a completely stock unrooted rom with stock recovery. After the phone is running the latest rom, then start with customization.

audit13 said:
Safest way to upgrade the modem and bootloader is via ota update on a completely stock unrooted rom with stock recovery. After the phone is running the latest rom, then start with customization.
Click to expand...
Click to collapse
I have the phone and managed to update it to 5.0 -> n9005xxugboa1
Is it the latest version or should I update it to another one?

BOD2 appears to be the latest according to sammobile.com: http://www.sammobile.com/firmwares/database/SM-N9005/

audit13 said:
BOD2 appears to be the latest according to sammobile.com: http://www.sammobile.com/firmwares/database/SM-N9005/
Click to expand...
Click to collapse
I'm from Portugal but the phone is unlocked (no carrier) and they only have firmware for carrier notes... Which one should I download and flash?
Also... with a G2 I flashed a .kdz file (official rom) and ended up with a bricked phone (later fixed via warranty), but I have no warranty in this phone, how can I make sure that the file is safe?

Just check for software updates from your phone.

audit13 said:
Just check for software updates from your phone.
Click to expand...
Click to collapse
It says the phone is already at the latest version. I've cleaned framework services and checked again but got the same result.

Try removing the SIM card and moving the date ahead by two days, then try again.

audit13 said:
Try removing the SIM card and moving the date ahead by two days, then try again.
Click to expand...
Click to collapse
Done that, no update avaiable. Connected to Kies3, no update avaiable.
Is it really in a old version? It's 5.0. Do I really need the latest version to start flashing a recovery?
Also, can I use the recovery without flashing it? I want to check if it works nicely before flashing if it is possible. TWRP can be used to flash any rom right? I'm interested in trying darklord first.

Yes, you can flash recovery without updating. I suggested updating because the update probably deals with the stage fright bug.

L720 Upgrading Modem and Android to Unlock Features

Current device:
L720, rooted android 4.2.2, baseband MF9, kernel kt-sgs4-08-09-2013, rom Negalite-WondeROM-r52.
What's up guys, I am just looking to upgrade to a newer android version and newer rom. When I've tried to update, I either usually lose data coverage or lose the ability to use the dialer. So my question is what kernel, modem, and rom version do I need to install to have access to the following features? -
Mostly, I just want to have my hotspot toggle on the pulldown menu (SQL editing hasn't worked for me), obviously native hotspot enabled, sound boosting mod, and to use emojis without installing an app that logs every key entry. I would also like to stay away from KNOX (even though I still don't fully understand what it does to the phones after being tripped?)
Do I need to unroot, let the updates come through OTA, then re-root and find a new rom for the android version?
Or do I do something like flash each android version by version until I'm all updated?
I've rooted and customized multiple phones with the help of xda, this is just the first time I haven't been able to solve my problem after many many tries at flashing. I am good with recovery, flashing, and odin, but I still don't totally understand differences in kernels, modems, and basebands.

I'd love a little help here too. Similar issues but on mf9 baseband and mk2 firmware, running SACs 4.3. I think twrp 2.6.3.
I'd love to know what I need to do to get my firmware updated and a working ROM installed. Please and thanks.

yall need to odin to at least the oldest version of the Android version you wish to move to. but first, you should know that the MF9 bootloader is a special one. it is one of the last Sprint bootloaders ever to not have a Knox trip.
this opens some opportunities for you -- upon updating via Odin, your phone would become a fresh knox 0x0 with valid warrantee (until your next root or TWRP) and also you could downgrade to the very first rom for the s4. I can't remember the fine details but I think it (MDC) was the only s4 rom that permitted some kind of CDMA editing or APN stuff. if interested you'll have to dig for whatever the perk was
if you want to update to jellybean 4.3, you'll need MJA* or MK2
*first bootloader on s4 both to prevent downgrading and include knox
for kitkat, odin NAE* or NG2**
*might permit downgrade to MK2
**notice! this is the final kitkat version! upgrading past here makes acquiring your MSL more difficult, so be sure to grab that first from any version NG2 or older and write it down. also, last s4 rom to (easily) UUIC unlock. it will stay unlocked
if you want lollipop 5.0.1 you'll need OD2* OH1** or OK3
*does not allow downgrade!
**some of the custom ROMs will require this version or newer.
I don't know if the s4 is one of them, but on some Sprint devices the APN settings are only (easily) accessible from roms with the XAS product code. factory default is SPR. you can change this with GalaxyTools (requires factory reset) or just odin the XAS version (might factory reset).
I know I might have created more questions than answered ...xda search & Google search are your best friends
edit: you can change your recovery to whatever you like, the only trick here is older recoveries don't like installing lollipop / marshmallow(CM13) ROMs -- I think TWRP 2.8 was the minimum? either way, just shoot straight for 3.0.2 there's nothing to lose.