Database Users

[Q] Flashing to different region firmware

Hi everyone
I've recently switched from the iCraps to a Galaxy Note 3 international version so I'm still really new at all this and trying to read up and learn what all the terminology means.
I want to flash my note 3 to another region's firmware. I've been reading all the forum posts and i'm getting conflicting information.
Im currently on AP: n900XXUBMI7, CP: n9005XXUBMI6, CSC: n9005XSABMI1
I just have a few questions:
1) I want to flash the UK firmware however i want the option to go back to the Australian firmware in the future without tripping knox. Which firmware is the best to use? I've been reading that updating to MJ3 wont allow u to downgrade or root the device without tripping knox
2) What does MJ6, MJ3, MI7 refer to? Is it the AP?
3) How do I go about flashing the firmware?
3)Can anyone link me to any good guides or webpages that will explain everything (like what AP and CSC mean and their significance?)
If you could point me to any other information that I should/need to know abouting flashing to other region's firmware that would be greatly appreciated. As I said I'm very knew to android, it's much more difficult to get ur head around compared to the iCraps

Hi,
I used this firmware BTU-N9005XXUDMJ7. If you do a Google search you should come up with it (That's what I did). I cam from the stock Virgin Australia rom (Which is really an Optus one).
Root first using the Universal Root de la Vega v0.2 method.
Purchase Mobil Odin Pro app from Google Play
When flashing I did not flash the modems, apparently this helps with downgrading to the stock Australian firmware is required (I am not sure if this is true as I have not tried it).
I've had no issues with it and flashed with mobile Odin twice using the same firmware as I have been experimenting with the Sony media apps to try and get everything working. Read the mobile Odin thread to get the lowdown on how to use it. To not flash the modems you select each section individually (you'll see what I mean in the app).
I only did this last night but haven't had any issues so far (other than me playing around with the system files and stuffing up).

[Q] New to note 3 & samsung

hi, i just got my note 3 n9005 international a couple of days ago & now its time to root...you can say i am a little new to samsung because the last device i used was an s3 & that was a long time ago.....
i dont have any warranty so knox isnt that big of a concern unless it may cause some sort of damage to the phone...so far i have read..its only for warranty purposes like the flash counter for s3.
i was wondering if anyone would be kind enough to point me to rooting & everything else i need to do to install custom roms including recovery...
i tried to read through the instructions of root de la vega but i find it too complicated...so i was thinking of doing cf auto root....
thank you

linx1287 said:
hi, i just got my note 3 n9005 international a couple of days ago & now its time to root...you can say i am a little new to samsung because the last device i used was an s3 & that was a long time ago.....
i dont have any warranty so knox isnt that big of a concern unless it may cause some sort of damage to the phone...so far i have read..its only for warranty purposes like the flash counter for s3.
i was wondering if anyone would be kind enough to point me to rooting & everything else i need to do to install custom roms including recovery...
i tried to read through the instructions of root de la vega but i find it too complicated...so i was thinking of doing cf auto root....
thank you
Click to expand...
Click to collapse
Samsung issue a 24month warranty on the Note 3 (maybe country specific?) -
If KNOX isn't an issue for you and you do not mind tripping it, the CF-Auto is the way to go.
RDLV is complicated if you're lazy, but it does preserve KNOX status depending on your bootloader version, put in #*1234# into your dial pad and post the results. We can know if you can use RDLV.
However, if you want to flash a Custom ROM, then you will need a custom recovery, which will trip your KNOX (can't be done without) - on the Android dev section and Orginal Android dev section (in this sub forum) are some Custom ROMs and the instructions on how to do so.
I have used X-Note, Crash and am currently using AllianceROM, but there are a few others.
Just be careful with custom kernels until you're pretty confident cause you can bootloop and ruin your EFS quite easily (it is fixable 99% of the time tho, script is on here also)
EDIT : All you need is here pretty much

thank you for your reply & these are the stats
AP: N9005XXUDMJ6
CP: N9005XXUDMJ4
CSC: N9005EVRDMJ4
also RDLV is way too complicated for me & besides i do plan to install a custom recovery so i think that defeats the point ....since you seem to have tripped knox, there hasnt been any kind of system issue i hope? this whole knox business gave me cold feet when i read about it...but so far as i can see..its just a flash counter.... could you tell me the tools i need to get started with? i already downloaded the usb drivers & odin 3.09..is there anything else i should need?
p.s. i was reading about "before or later MJ7 4" whatever...& i was wondering which of these was it refering to? ap? thank you

Once you trip the knox counter it makes no difference to the phone except not being able to use knox containers, and of course the warranty which you know. -- if you have the drivers and odin. Go grab cf-autoroot, run it thru odin and voila all done, similar for twrp or Cwm which ever you choose as your custom recovery (I use twrp) flash in odin and that's it all set.
Just make sure and I can't stress this enough, that you flash the right ROM for the N9005, and N900 doesn't work. - avoid doing restores with twrp for now also when you do a back up, some issues have arose recently and not sure of they're resolved or not yet.
Have fun man, just read everything about the ROM etc before you flash the odd one has FC's or NFC issues
Sent from my SM-N9005 using XDA Premium 4 mobile app

ok so backing up & restoring with recovery is, for the time being, a no no? yes i will make sure to see if the roms are made for n9005 only....i will probably start off with omega roms as they are the 1st choice i had when i started modding the s3 ....thank you soo much mate for all the info...1 last thing to clear up is i am reading on developers talking about MJ or MK or whatever it is....are they talking about the build number i find in Settings/About??

1 thing i couldnt get a proper answer for...is how does 1 know they have the international variant of the n9005 anyway? normally if a n9005 is under some sort of carrier...the carrier logo would flash when booting up right? because thats what happens on my brother's note 3 n9005...when he boots up his phone..it shows SFR logo before going to the samsung bootanimation.....but on mine there is no such thing...the simple note 3 n9005 text then samsung boot animation & then straight to system...that means mine is the unbranded 1 am i correct?

linx1287 said:
1 thing i couldnt get a proper answer for...is how does 1 know they have the international variant of the n9005 anyway? normally if a n9005 is under some sort of carrier...the carrier logo would flash when booting up right? because thats what happens on my brother's note 3 n9005...when he boots up his phone..it shows SFR logo before going to the samsung bootanimation.....but on mine there is no such thing...the simple note 3 n9005 text then samsung boot animation & then straight to system...that means mine is the unbranded 1 am i correct?
Click to expand...
Click to collapse
Yeah yours is unbranded, only thing that may/will apply to you is region lock (which unless you're leaving the country your purchased your phone in isn't an issue at the start.
Although I see your CSC is EVR (if I recall correctly that is EE UK's firmware on board)
EDIT: Yes MK/ML are build numbers

no i dont have region lock..THAT i checked...so can i go forwards with all the rooting recovery & custom roms? i did find a orange core services apk on my apps manager under ALL tab..... also what original firmware can i roll back to incase anything goes wrong? any specifics?

linx1287 said:
no i dont have region lock..THAT i checked...so can i go forwards with all the rooting recovery & custom roms? i did find a orange core services apk on my apps manager under ALL tab..... also what original firmware can i roll back to incase anything goes wrong? any specifics?
Click to expand...
Click to collapse
Yup can go forwards. EVR (EE aka Orange/T-Mobile) have unlocked phones so yeah you won't have region lock. Which means yours is unbranded but carrier unbranded.
As for firmware, it depends on what region you are using? And what country you are in (you could use BTU (also UK, unbranded but EVR is ok also) - You are **now I say this depending on your country/region** OK on MJ7 or MK2 IF you upgrade since you're using a UK based ROM/CSC your network obviously supports it. However battery life is better on lower than MJ6. So it's your choice really.
Most custom ROMs are MK2 or ML2 atm I think, - Not sure if any upgrade your bootloader to MJ7 (if they do, you can't roll back any lower currently)

i just need a stock firmware so as i have a fallback if anything goes wrong...nothing more really as i plan to stick with custom roms...will this do?
http://samsung-updates.com/details/17028/Galaxy_Note_3_Snapdragon/SM-N9005/EVR/N9005XXUDMJ6.html
i am in Bangladesh so i am pretty confident that there isnt any rom for my region
yea i was wondering about the battery life myself...i dont know what version my brother's note is but his battery lasts noticibly longer than mine does....i was even planning on swapping batteries as i thought it might be a cell related issue

linx1287 said:
i just need a stock firmware so as i have a fallback if anything goes wrong...nothing more really as i plan to stick with custom roms...will this do?
http://samsung-updates.com/details/17028/Galaxy_Note_3_Snapdragon/SM-N9005/EVR/N9005XXUDMJ6.html
i am in Bangladesh so i am pretty confident that there isnt any rom for my region
yea i was wondering about the battery life myself...i dont know what version my brother's note is but his battery lasts noticibly longer than mine does....i was even planning on swapping batteries as i thought it might be a cell related issue
Click to expand...
Click to collapse
As long as your bootloader doesn't go to MJ7 - that firmware is OK, If your bootloader updates ( I think it may with the custom ROM) you can't roll back to MJ6, you can go to MJ7 or MK2 via BTU which will work for you since EVR works.

the latest omega is ML2 so by that measure...i wont be able to roll back to MK2 either & the latest on this thread http://forum.xda-developers.com/showthread.php?t=2459328 is MK2

linx1287 said:
the latest omega is ML2 so by that measure...i wont be able to roll back to MK2 either & the latest on this thread http://forum.xda-developers.com/showthread.php?t=2459328 is MK2
Click to expand...
Click to collapse
You can drop back as far as MJ7 ( I have at least when I've returned to stock due to mess ups) my build is MK2 atm
the bootloader only goes to MJ7 (last I checked, If it has changed then mine still lets me roll to MJ7)

csc seems a very complicated mess...GOD when did the mod friendly samsung go this crazy? the s3 was the most fun thing to mod...now this feels more complicated then Sony's!! :'( since my csc is EVR...is it possible to put BTU? i saw someone post this but didnt get any replies... http://www.usofttech.com/t128991.html
OH CRAP you said this BTU already...sorry my bad.... just trying to absorb all this

1 last query & i think i can start....with my current MJ6 build...can i do the cf auto root? or do i need to be on a lower build? if i can...then i think i will start or should i wait for the MJ7 to finish downloading & root that with cf auto root? & mate...thank you... you helped clear a lot of the confusions stopping me from modding this...now i think i can start things with a bit of confidence...thank you.... MUCH appreciated

linx1287 said:
1 last query & i think i can start....with my current MJ6 build...can i do the cf auto root? or do i need to be on a lower build? if i can...then i think i will start or should i wait for the MJ7 to finish downloading & root that with cf auto root? & mate...thank you... you helped clear a lot of the confusions stopping me from modding this...now i think i can start things with a bit of confidence...thank you.... MUCH appreciated
Click to expand...
Click to collapse
You can CF root straight away, - since you're triggering KNOX anyway it won't affect you. Then on with custom recovery etc, just keep MJ7 as your stock back up on your PC just incase. and IF you run into any issues with EFS (bootloops/no signal/wifi/baseband etc) use THIS It has saved me and quite a few others.
EDIT: And no problem man, glad to help, we all start somewhere with new devices

mate....the odin inside the cf root is 1.85 & the 1 got from google is 3.09 which should i use? & is PDA & AP the same thing because they are diff in the 2 versions of odin

linx1287 said:
mate....the odin inside the cf root is 1.85 & the 1 got from google is 3.09 which should i use? & is PDA & AP the same thing because they are diff in the 2 versions of odin
Click to expand...
Click to collapse
I use 3.07 personally - and flash using PDA -- Use the one with CF root if you're unsure

the phone is rooted ahhh feels like home again ....mate you said earlier that restoring backups on twrp causes system issues....i was wondering if this is true for just twrp or ALL current recoveries in general? which recovery would you suggest? also i was wondering about that script you told me about...the 1 about soft brick.... that fixes corrupt efs due to flashes yes? if so, does that mean it doesnt require my backup of efs?

linx1287 said:
the phone is rooted ahhh feels like home again ....mate you said earlier that restoring backups on twrp causes system issues....i was wondering if this is true for just twrp or ALL current recoveries in general? which recovery would you suggest? also i was wondering about that script you told me about...the 1 about soft brick.... that fixes corrupt efs due to flashes yes? if so, does that mean it doesnt require my backup of efs?
Click to expand...
Click to collapse
TWRP has issues *sometimes* there's a few posts about it around, I personally have had no problems and use TWRP fine, but I mentioned it because what works for one, doesn't always for another.
As for EFS backup, keep it just incase -- IT seems Android can rebuild the EFS again with that fire script. -- It's handy though, gotten a few out of the crapper including myself

[Q] Can I upgrade to 4.4?

So when I first got my note I imediately used this guide to flash kitkat and completely ****ed it up, it just stuck on the Samsung n9005 screen.
This was a link to C4ETech's video called "Galaxy Note 3 - Samsung Official Kitkat 4.4.2 - How to Flash/Install" but I had to remove it.
I assumed it was something to do with the CSC code (mine being BTU) so I installed a BTU rom using this guide.
This was a link to TheSmokingAndroid's video called "HOW TO UNBRICK & UNROOT SAMSUNG GALAXY NOTE 3" but I had to remove it.
Now I want to install a kitkat rom preferably a stock one but there isn't one for BTU. So I looked at the custom roms as some support BTU but require the device to be on 4.4 already. How can I get onto 4.4 if every 4.4 rom requires a 4.4 phone? Will I have to wait until an official BTU update comes out?
I've attached a screenshot of my About Phone page (which doesn't have BTU anywhere, I don't get it).
I probably have the complete wrong end of the stick so sorry for wasting everyone's time but if you have a minute to help I'd really appreciate it.

HelloMyNamesTom said:
So when I first got my note I imediately used this guide to flash kitkat and completely ****ed it up, it just stuck on the Samsung n9005 screen.
This was a link to C4ETech's video called "Galaxy Note 3 - Samsung Official Kitkat 4.4.2 - How to Flash/Install" but I had to remove it.
I assumed it was something to do with the CSC code (mine being BTU) so I installed a BTU rom using this guide.
This was a link to TheSmokingAndroid's video called "HOW TO UNBRICK & UNROOT SAMSUNG GALAXY NOTE 3" but I had to remove it.
Now I want to install a kitkat rom preferably a stock one but there isn't one for BTU. So I looked at the custom roms as some support BTU but require the device to be on 4.4 already. How can I get onto 4.4 if every 4.4 rom requires a 4.4 phone? Will I have to wait until an official BTU update comes out?
I've attached a screenshot of my About Phone page (which doesn't have BTU anywhere, I don't get it).
I probably have the complete wrong end of the stick so sorry for wasting everyone's time but if you have a minute to help I'd really appreciate it.
Click to expand...
Click to collapse
Try *#1234# might come up there. Anyways, go over to Sammobile and grab any of the latest 4.4.2 KitKat ROMs for your device (9005) as you said. And it should work fine.
Advice: Wipe your phone, not compulsory but advisable. Cheers!

I have a canadian variant note 3 900w8 and i want to flash 4.4.2 as well but i was hoping to flash the t-mobile version as i have heard of issues with the 9005 rom compatibility, just wondering if anyone has had experience yet, or if it has been done.

stanley08 said:
Try *#1234# might come up there. Anyways, go over to Sammobile and grab any of the latest 4.4.2 KitKat ROMs for your device (9005) as you said. And it should work fine.
Advice: Wipe your phone, not compulsory but advisable. Cheers!
Click to expand...
Click to collapse
Thanks for your help but I've already done that and the newest version I can get is 4.3 I'll just wait until my phone gets the update, Thanks anyway

I've managed to get onto 4.4 now by flashing a polish ROM after reading that they support BTU, I don't know how to delete this thread so I'm just letting everyone know my issue is resolved

Jagerfarts said:
I have a canadian variant note 3 900w8 and i want to flash 4.4.2 as well but i was hoping to flash the t-mobile version as i have heard of issues with the 9005 rom compatibility, just wondering if anyone has had experience yet, or if it has been done.
Click to expand...
Click to collapse
If you want the ability to flash back to 4.3 from 4.4, install custom recovery and roms and keep your Knox 0x0, head over here and do some reading ( if you haven't been there already ).

[Q] Kernel issue or bricked?

Yesterday I tried to upgrade my Galaxy S4 (Canadian, Telus SGH-I337M) to lollipop. I came here and installed the latest Cyanogenmod successfully using the posted instructions. Unfortunately, BlueTooth wasn't working so I decided to uninstall it.
I then thought I'd try CM11 via their auto installer. After taking the phone back to factory settings, I ran the CM installer and got CM11 installed instead. Except with that, my phone lost all audio. No phone communication, no rings, nothing.
So I tried going back to stock and I downloaded and installed the 4.4.2 stock ROM... expect now I have no wi-fi functionality, and a couple of other weird behaviors like very, very slow screen response.
The most likely answer I've found is that somewhere in this process, I flashed the kernel and now my kernel is incompatible with my ROM. I've found what I think is the right kernel, but I can't install it. All of the instructions say to use ODIN, but ODIN restricts me to putting specific file extensions in the box, but these files come as .RAR or .ZIP, and the contents of the archive don't have any of the allowed file extensions (i.e. .BIN files).
At this point, my priority is just getting a working phone again by any means necessary - I don't care whether it's a custom ROM or not, I just want functionality on all of my phone at once! I'm not computer illiterate, but at this point I've outstripped my troubleshooting capability.
Help?
System info that may help:
Model Number: SGH-1337M
Android version: 4.4.2
Baseband version: I337MVLUAMDJ
Kernal Version:
3.4.0-2767305
[email protected] #1
Mon Sep-29 13:01:35 KST 2014
Build Number: KOT49H.I337MVLUFNI2
SE for Android Status:
Enforcing
SEPF_SGH-I337M_4.4.2_0028
Mon Sep 29 13:01:15 2014
Secure boot status: Type: Samsung

Try installing the stock ROM a second time over the top of your first install of the stock ROM. For some unknown reason installation through Odin doesn't always result in a perfectly functioning device the first time around. Installing the ROM a second time however tends to fix things.

Did you download your stock firmware from sammobile.com?
The firmwares from that site should work fine in Odin.

I've gone through a few stock ROMs. The one I'm working with now seems to be the right one. It's I337M_TLS_I337MVLUFNI2_I337MOYAFNI2_Original.zip
SamMobile says those are the right ones, and I have installed it over itself... repeatedly!
I've done more trouble shooting now and I have issues regardless of what ROM (CM12 or stock 4.4.2) I install. The issues between the two are different in some regards but in either case, the phone is more or less toast!
- Phone calls are VERY slow to respond in both (when I try to make a call, even though I know I have no audio capability).
- No audio at all
- on Stock 4.4.2, no wifi
- Screen is slow to respond on stock, particularly when dismissing the lock screen.
- On CM12, Bluetooth and wifi can't be enabled simultaneously
- CM12 won't play videos (didn't try on stcok)
What have I done?!

Update:
Using a different file recommended by Sammobile (they have more than 1 listed for this phone on their site), and DLing it directly from them , I seem to have stock functionality back. Yaaa!
The most recent ROM (ending in FNI2) didn't work but when I went back to a build about 6 months older (ending in FNC1) that one worked out.
I guess the question then remains: What went wrong, and is there a ROM that should theoretically work for this phone?
Thanks!

RCNBob said:
Update:
Using a different file recommended by Sammobile (they have more than 1 listed for this phone on their site), and DLing it directly from them , I seem to have stock functionality back. Yaaa!
The most recent ROM (ending in FNI2) didn't work but when I went back to a build about 6 months older (ending in FNC1) that one worked out.
I guess the question then remains: What went wrong, and is there a ROM that should theoretically work for this phone?
Thanks!
Click to expand...
Click to collapse
You are flashing wrong CSC maybe. Solution:
1. Verify your CSC. Use this APP for know your real CSC. (Pic 1)
2. Go to Sammobile again and download the correct and latest firmware for your CSC.
3. Unzip and flash that firmware via ODIN.
4. Dial *#1234# and tell me what appears :highfive:

Joku1981 said:
You are flashing wrong CSC. Solution:
1. Verify your CSC.
2. Go to Sammobile again and download the correct and latest firmware for your CSC.
3. Unzip and flash that firmware via ODIN.
4. Dial *#1234# and tell me what appears :highfive:
Click to expand...
Click to collapse
1. CSC shows:
Original CSC Code: TLS
Firmware's CSC Code: TLS
Active CSC Code: TLS
CSC Country: Canada
CSC Country ISO: CA
Product Code: SGH-I337ZKATLS
2. After a couple of OTA Updates overnight, the phone is now using firmware I337MVLUFNI2, which is the one I tried from SamMobile that failed, so I had to use a six month older build. which worked fine for some reason.
3. AP, CP, and CSC all show I337MVLUFNI2 now.
I'm now very reluctant to try any custom ROM on this phone after spending 30 hours worrying that I had bricked it! I tried about 5 different ROMs throughout this process that all had varying degrees of that same issue. Is the Canadian S4 SGH-I337M that much different from the i9505? Did I just screw something up royally? I'm happy that my phone is working now, but I'd still like to know what went wrong, or whether customs ROMs are an option for me.

RCNBob said:
1. CSC shows:
Original CSC Code: TLS
Firmware's CSC Code: TLS
Active CSC Code: TLS
CSC Country: Canada
CSC Country ISO: CA
Product Code: SGH-I337ZKATLS
2. After a couple of OTA Updates overnight, the phone is now using firmware I337MVLUFNI2, which is the one I tried from SamMobile that failed, so I had to use a six month older build. which worked fine for some reason.
3. AP, CP, and CSC all show I337MVLUFNI2 now.
I'm now very reluctant to try any custom ROM on this phone after spending 30 hours worrying that I had bricked it! I tried about 5 different ROMs throughout this process that all had varying degrees of that same issue. Is the Canadian S4 SGH-I337M that much different from the i9505? Did I just screw something up royally? I'm happy that my phone is working now, but I'd still like to know what went wrong, or whether customs ROMs are an option for me.
Click to expand...
Click to collapse
If you dial *#1234# and appears this all is solved:
AP: I337MVLUFNI2
CP: I337MVLUFNI2
CSC: I337MOYAFNI2

Joku1981 said:
If you dial *#1234# and appears this all is solved:
AP: I337MVLUFNI2
CP: I337MVLUFNI2
CSC: I337MOYAFNI2
Click to expand...
Click to collapse
Yes,
That seems to be the case, but should I have been safe in trying to install a custom Lollipop ROM? I'm kind of in a 'once bitten twice shy' state of mind now. I'd like to go to 5.0.2 but after this, I'm not so sure.

RCNBob said:
Yes,
That seems to be the case, but should I have been safe in trying to install a custom Lollipop ROM? I'm kind of in a 'once bitten twice shy' state of mind now. I'd like to go to 5.0.2 but after this, I'm not so sure.
Click to expand...
Click to collapse
How you wish. But remember that Lollipop stock firmware for your device is a leak still or you can try with different custom roms. You will have BUGS. If the device was mine I will wait for the OTA updates but it's only my opinion. I'm not desperate for Lollipop :highfive:

Joku1981 said:
I'm not desperate for Lollipop :highfive:
Click to expand...
Click to collapse
You would be if you had used it, it's frickin awesome

Downgrade 6.0.1 to 4.4.2 or 5.1.1 ?

Hi Guys,
New to this device, but not new to Android... Read all over the web, various sites (esp this one) about this device and seeing mixed views/comments. Some saying its possible, others saying it will brick or flag the Knox.
Is it possible to downgrade this phone (G900F) currently on the latest 6.0.1 stock rom. But was wondering if I could try either official stock of 4.4.2 or 5.1.1 of this device.
Or due to this bootloader, is it likely to brick or even trip Knox?
Thanks, Lister

Lister Of Smeg said:
Hi Guys,
New to this device, but not new to Android... Read all over the web, various sites (esp this one) about this device and seeing mixed views/comments. Some saying its possible, others saying it will brick or flag the Knox.
Is it possible to downgrade this phone (G900F) currently on the latest 6.0.1 stock rom. But was wondering if I could try either official stock of 4.4.2 or 5.1.1 of this device.
Or due to this bootloader, is it likely to brick or even trip Knox?
Thanks, Lister
Click to expand...
Click to collapse
Official stock ROMs shouldn't trip Knox because they are, ummm, official.
I think the G900F bootloader is unlocked.
Sent from my Samsung SM-G900I using XDA Labs

Why downgrade in the first place..... ? 6.0.1 is way better than previous FWs...

Hi @Dirty Flasher,
Yeah, that's what I thought... It's all stock, so all should be good... But I've read reports saying it will trip Knox as since a certain version of Marshmallow, the bootloader has been locked to only go with future firmwares and not allow downgrades. I assume to prevent people restoring to the older firmware (with bootloader) which was unlocked, that allowed rooting without tripping. But some say it will trip, others say it will not... I'm confused, and wondered if anyone has tried this, and what the outcome was... Don't want to trip Knox unnecessarily... if someone has already tried and tested it.
Dirty Flasher said:
Official stock ROMs shouldn't trip Knox because they are, ummm, official.
I think the G900F bootloader is unlocked.
Sent from my Samsung SM-G900I using XDA Labs
Click to expand...
Click to collapse
Hi @Zlate2255,
I got this device when it was already one 6.0.1, so I missed seeing it go through the various stages. I would like to see how it used to look like and work. As there are some features that have been removed since, such Face Unlock and Iris tracking when viewing pages. Whilst the latter is still there burried away, it barely works, so should be removed completely. But would just be nice to see what it did look like.
Zlate2255 said:
Why downgrade in the first place..... ? 6.0.1 is way better than previous FWs...
Click to expand...
Click to collapse
Thanks, Lister

With my G900W8, I could downgrade to 4.4.2 with very-first firmware for G900W8 (NCG). Just try the earliest version of 4.4.2 and then upgrade back to 5.1.1

You can downgrade the g900f to every firmware (if unlocked) you want. On some s5 devices who have a locked bootloader like the at&t version there have been reported some problems.
Therefore, you shouldn't run into any problems while downgrading.
If you want some pro and cons to the firmwares:
Kitkat:
+ dark design (the touchwiz apps like contacts)
+ more battery friendly than marshmallow
- less security due to no security updates
- you might run into some minimal bugs, for example on wikipedia you sometimes have to reload the page to watch pictures (at least on mine)
- no app permissions can be removed (only with root and app ops)
Lollipop:
Honestly, I havent used this one that much, but here you have a white design with the different statusbar and pull down menu, better security (but not as good as on marshmallow) and the material design, but slightly worse battery time.
Marshmallow:
+ OTA Updates still available, best option for security
+/- White design, material design
+ new icons (but tbh not a real deal)
- less battery friendly (atleast for me even tho doze is enabled on marshmallow)
So yeah, choose what you want
And be sure that you have an unbranded device (check your csc) before downgrading/updating.

Hi @tm60405,
Wow, what a fantastic post... Thank you, exactly what I was looking for, and thanks for your reviews of each rom too.
- appreciate that, cheers
Quick question, how do I know if my Bootloader is unlocked??
Its a G900F (UK) was originally on the Three network, however I've flashed it to pure stock BTU, and to the EE network and back to stock BTU (all Marshmallow roms).
So where am I looking, or how do I know if the Bootloader is unlocked? Also, what am I looking for in the CSC info...??
Many thanks, Lister

Install the app called phone info from the play store.
Then, you swipe to the csc code and you can see your info and remember the csc you are on.
If it is BTU, you can install another firmware based on BTU without problems. But even if you don't have BTU, you can try installing BTU because it doesn't contain much bloatware. In the worst case, you just install the firmware with the csc you had before.
Then, follow the instructions on sammobile.com and there will be no problems during the installing process.
After downgrading, you might get a bootloop. Then, you have to factory reset your device, so get the data from the internal storage elsewhere BEFORE the installation.
And if the download takes too long, try another browser like opera, for me it takes around 1 hour only instead of 4-5 hours on chrome.
If you might have another problem while installing the firmware, say so.