Database Users

[Q] Damaged EFS, no backup - how to repair S5 with NULL IMEI?

Hi,
I have a problem with my S5. After flashing a custom ROM I found out that my IMEI is null, and so the EFS is corrupted. I tried to restore it from backup only to find out that I have deleted the backup
What can I do now? I anything? Would restoring EFS from another S5 (with damaged mainboard) could be a solution?
Generally everything works except of phone modem, I have got IMEI written - is there maybe a method to set the IMEI without EFS or a method to create EFS? I already tried sam IMEI changers, but I found out that they only do this on the application level - apps will be able to read different IMEI for licensing, but phone still sees NULL IMEI.

You can't restore EFS from another S5 coz it'll brick your device.

Bruce666 said:
You can't restore EFS from another S5 coz it'll brick your device.
Click to expand...
Click to collapse
Thanks for answer
So what can I do?

Found sth like this:
Never tried coz never lost IMEI
In the dialer, type- *#197328640# or *#*#197328640#*#*
>You will be prompted into the Command mode, provided On the screen, Select on Common, normally option 6
> Now Select (FTM) Option 1
>FTM is for debugging and testing., (Field Test Mode)
>If (FTM) is on, you will have to turn this OFF
>As soon as you turned this off your NULL or altered IMEI number will be restored
>(Important) Without leaving the Command screen, press the Menu key, the button that’s found left of the Home button.
> Select Key input and enter option 2. In this case, you want to turn it off
>Wait for a minute. This will turn your FTM OFF
> Remove your battery and SIM card for two minutes
>Place your battery in your phone, (important) do not place your SIM card in.
> When the phone is booted, enter the command mode again dial – *#197328640#
>Select the Debug Screen, normally option 1
>After that, choice phone control, option eight
>Click on nas control, option 3
>Afterwards, click “RRC (HSDPA), option 5
>To Fix not registered on network or Null IMEI #, click RRC revision, option 2.
>Choose the released of your phone, here we will choose option 5 (HSDPA only)
>Final step to fix Null IMEI not registered on a network for Samsung Galaxy is to turn off your phone and insert your Sim card
or
>Insert your Sim card, afterwards reboot your phone

Thanks - are you sure about this bricking device?
I already tried this numbers but it always says "No Network", The only instruction that I found was to use *#0011# and it goes into the Service Menu, but it doesn't look like that described. There is something called NVM restore, but it doesn't do anything with IMEI
I am gonnna post screenshots at evening.
Bruce666 said:
Found sth like this:
Never tried coz never lost IMEI
In the dialer, type- *#197328640# or *#*#197328640#*#*
>You will be prompted into the Command mode, provided On the screen, Select on Common, normally option 6
> Now Select (FTM) Option 1
>FTM is for debugging and testing., (Field Test Mode)
>If (FTM) is on, you will have to turn this OFF
>As soon as you turned this off your NULL or altered IMEI number will be restored
>(Important) Without leaving the Command screen, press the Menu key, the button that’s found left of the Home button.
> Select Key input and enter option 2. In this case, you want to turn it off
>Wait for a minute. This will turn your FTM OFF
> Remove your battery and SIM card for two minutes
>Place your battery in your phone, (important) do not place your SIM card in.
> When the phone is booted, enter the command mode again dial – *#197328640#
>Select the Debug Screen, normally option 1
>After that, choice phone control, option eight
>Click on nas control, option 3
>Afterwards, click “RRC (HSDPA), option 5
>To Fix not registered on network or Null IMEI #, click RRC revision, option 2.
>Choose the released of your phone, here we will choose option 5 (HSDPA only)
>Final step to fix Null IMEI not registered on a network for Samsung Galaxy is to turn off your phone and insert your Sim card
or
>Insert your Sim card, afterwards reboot your phone
Click to expand...
Click to collapse

evilsnailofdestruction said:
Thanks - are you sure about this bricking device?
I already tried this numbers but it always says "No Network", The only instruction that I found was to use *#0011# and it goes into the Service Menu, but it doesn't look like that described. There is something called NVM restore, but it doesn't do anything with IMEI
I am gonnna post screenshots at evening.
Click to expand...
Click to collapse
Yes I'm sure about bricking. EFS partition on your phone is made for ONLY YOUR PHONE. This is sth like restoring TA Partition on xperia devices. When you flash ta from another xperia, you brick device
Tapatalked from SM-G900F

I read someone saying they had successfully restored a backed up EFS partition from an identical model S5 to another, and it worked
The problem I can see, is if the original gets blocked by the carrier, chances are so will the clone
Not sure about network issues having two identical devices on the same network at the same time, both making calls, might end up like an IP conflict

Pretty sure that transferring IMEI from one device to another is against the law too......
Sent from my rooted, debloated stocKK kn0x0 SM-G900F

Yes, I also know that is it against the law, but I have a complete phone with broker mainboard (so even the IMEI is written on the back), and I would like to use this opportunity to copy the IMEI from old (broken) mainboard to the new one. It even looks better than the situation when I have got and old case with written IMEI that doesn't correspond to the IMEI on the new mainboard.
The mainboard is broken that way, that there is short-circuit somewhere and the CPU is constantly using power and it get's really hot, so it use useless.
I am trying to flash EFS, let's see what is gonna to happen
keithross39 said:
Pretty sure that transferring IMEI from one device to another is against the law too......
Sent from my rooted, debloated stocKK kn0x0 SM-G900F
Click to expand...
Click to collapse

1. Tried flashing EFS = nothing happened
2. Tried flashing EFS + Modem + ModemST1 + ModemST2 = nothing happened
3. Restored android to STOCK
I can't get into the service menu.
The only Service menu that I can get into is this one, but there isn't any fixing IMEI/NVRAM option
Code:
*#0011#
Menu > Back
Menu > keyInput "Q"
Menu > keyInput "0000"
Wait for few seconds
evilsnailofdestruction said:
Yes, I also know that is it against the law, but I have a complete phone with broker mainboard (so even the IMEI is written on the back), and I would like to use this opportunity to copy the IMEI from old (broken) mainboard to the new one. It even looks better than the situation when I have got and old case with written IMEI that doesn't correspond to the IMEI on the new mainboard.
The mainboard is broken that way, that there is short-circuit somewhere and the CPU is constantly using power and it get's really hot, so it use useless.
I am trying to flash EFS, let's see what is gonna to happen
Click to expand...
Click to collapse

Hi,
you have 2 options
1. Use Samsung Kies which will repair you efs
2. Flash with Odin the official rom 5.0
If you install another efs, the data installed may be not work, even if it is same model. In S5, nothing to do with the IMEI
You can also root the phone and with adb commands, erase all the efs
you can also use Z3X tools

Hi,
Thanks - some new ideas
So if I understand you correctly, I have 3 options:
1. Use Samsung Kies which will repair you efs - how to repair EFS with Samsung Kies?
2. Flash with Odin the official rom 5.0 -> I tried flashing oryginal 4.4 and it didn't helped. Should flashing 5.0 help?
3. You can also root the phone and with adb commands, erase all the efs - What will erasing EFS will give me? Shouldn't I have EFS partition with some data?
you can also use Z3X tools -> ok... I am gonna figure this out, 'cause I don't know it yet
FrenchSnake said:
Hi,
you have 2 options
1. Use Samsung Kies which will repair you efs
2. Flash with Odin the official rom 5.0
If you install another efs, the data installed may be not work, even if it is same model. In S5, nothing to do with the IMEI
You can also root the phone and with adb commands, erase all the efs
you can also use Z3X tools
Click to expand...
Click to collapse

I have the same issue. Anybody may help me ? (galaxy S5 SM-G900H made in Vietinam)
thanks in advance

Bruce666 said:
Found sth like this:
In the dialer, type- *#197328640# or *#*#197328640#*#*
>Insert your Sim card, afterwards reboot your phone
Click to expand...
Click to collapse
This does nothing on Galaxy A5!
attached 0011 code screen

Has anybody found the solution? Efs professional gives me error " device connection lost" while using Qualcomm nv tools on s5.

SM-g550t2 unlock

Any method to unlock this phone without paying for it or having to wait 90 days yet?

This is what I tried with CG Pro Key
I read online that it is done with the same method as the SM-G550T1, so I am trying it on a SM-G550T2 this precise moment. I am not responsible for any problems that may arise with your phone if this does not work for you, I have tried it on several SM-G550T1 from Metro PCS and it has worked well.
1. Power on phone, go to apps>settings>about phone, then tap on Build number seven times to enable developer options, once message prompts about being a developer.
2. Go back to settings and look for the "developer options", go there and make sure "OEM Unlock" is selected, as well as "USB debugging".
3. Download the following three files, I tried posting the download links but since I hardly ever post upon forum policy I am not able to, if you need the files PM me.
3a. Odin 3.10.7 is the version I have used and has worked for me
3b. TWRP custom recovery, should be installed Using Odin. Put phone in Download Mode (Home+Power+Vol-) and connect to computer then open Odin.exe using right click and running as administrator. Once opened select the "AP" box and select the TWRP file, then click on start, once Odin finishes it will restart phone. Once this happens remove the battery, because I let it fully restart once even after Odin showed the PASS, and when I tried entering Recovery Mode it went into OEM Android recovery.
3c. SuperUser Root. Once the TWRP custom recovery has been installed save the SuperUser file in an SD card and insert it on the phone OR save it directly to your phone's internal storage, then put phone in Recovery Mode (Home+Power+Vol+). Once in recovery mode you will get a screen with a disclaimer, just "Swipe to Allow Modifications", then select "Install", then on the bottom "Select Storage" and go to wherever you saved your file and select it, then "Swipe to confirm Flash" and wait for phone to finish, then select Reboot option.
UP TO THIS POINT your phone has a custom recovery and SuperUser access, I have only unlocked these phones using GC Pro since its the method that has worked for me, but theoretically you could be able to test with z3x o octoplus, Processor is Exynos from what I have read on other forums it should work using models g920t o g925t, but I haven't tried that so I can't vouch for these to work. IF YOU PLAN TO DO SO, DO IT AT YOUR OWN RISK
4. Connect your GC pro Key or Box as well as your phone, and open GCPROGSMTOOLKIT. Once program starts go to Samsung tab, select any of the models, it does not make any difference, then under "Service" select "TMOBILE Unlock" and click on "Start", the phone will prompt for computer connection, then will ask for permission fomr SuperUser, Grant it then sit back and wait, the box will finish and restart phone:
Using Version...1.0.0.0047
Selected Model GT-I5503
Selected Task SAMSUNG T-MOBILE UNLOCK
Searching ADB device Please wait..
Device Detected...
model:= SM-G550T2
Androids Version:= 6.0.1
Description Version:= on5ltetmowal-user 6.0.1 MMB29K G550T2UVU2AQC4 release-keys
Platform:= exynos3 [ universal3475 ] [ SHANNON308 ]
Baseband:= G550T2UVU2AQC4
VER:= G550T2UVU2AQC4/G550T2TMB2AQC4/G550T2UVU2AQC4/G550T2UVU2AQC4
Carrier := TMB_USA
AP UART Status := Disable.
Security Patch := 01-03-2017
Network Mode := LTE
Simstatus:= ABSENT
ANDROID-ID = 920110f5341e24df_0000D5E046
SU Version..2.77:SUPERSU
Device is Secure Rooted..uid=0
System Permission is Read/Write...
SAMSUNG ALL T-MOBILE UNLOCKING STARTED...
Checking Data...
Waiting for Loader...
Loader Ok...
Direct Unlock Success...
!!! Success !!!!
Restart Phone Manually if not done auto...
Total Time Take...00:00:09
Log Saved
Afterwards insert a SIM card and enjoy your unlocked phone, I just did it as I typed all the process for you on a Wal Mart family mobile SM-G550T2 and it worked no problem, hope this is helpful to you

willing to pay $

hi, i have s7 edge sm-g935a pk1 and i got tired from trying to fix it. it got stuck on at&t logo and i tried everything! i found in this forum.
i odin it successfully and nothing.
when im in recovery mode i get: "dm-verity verification failed " and "update from external storage is disabled"
please help meeeee
thanks

What is broken?

Hi,
To fix this, you need to use an application called Samsung smart switch on your computer.
1. Download Samsung smart switch onto your computer and install.
2. After it finishes installing, plug your device into your computer using your USB charging cable.
3. On your device boot into the bootloader by pressing, power+volume down+home.
4. When you get to the bootloader it will warn that installing a custom OS may harm your device. Ignore this and press the home button.
5. You will see a few different barcodes and numbers. Copy down the ones labelled S/N (or SN) and IEMI.
6. Now, press home again and stay in the bootloader. Copy down the model number of your phone displayed in the top left corner of the screen.
7. Smart switch will not recognize the phone, but it will still work.
8. In smart switch, click more, then Emergency Software Recovery and Initialization.
9. Where it says Model name, type in your model number. (Ex. SM-G935A)
10. Click search, then type in the S/N or SN number that you copied down from before.
11. Click OK, and when the dialog window comes up, click ok again.
12. A dialog box will appear that shows what is going to be installed on your phone. Click OK.
13. Yet another dialog box will appear telling you to enter the bootloader. If the OK is grayed out double check that your device is plugged into your computer. If it is not, plug it in. If it is, unplug it from your computer and plug it back in. The drivers may install, but eventually the OK will turn blue.
14. Click Ok. It will download the required firmware. This may take some time. DO NOT UNPLUG YOUR DEVICE.
15. When it is done downloading it will flash onto your device.
16. Your device will restart after flashing and the boot will take some time.
Your phone will be factory restored during this process. If it doesn't work follow the steps again but very carefully. Here is a video that you can use to help you out:
I will not accept any money that you offer me as I have been through this situation before and I understand the struggle and stress that it may cause.
TomatoesOnBluRay

thanks
TomatoesOnBluRay said:
Hi,
To fix this, you need to use an application called Samsung smart switch on your computer.
1. Download Samsung smart switch onto your computer and install.
2. After it finishes installing, plug your device into your computer using your USB charging cable.
3. On your device boot into the bootloader by pressing, power+volume down+home.
4. When you get to the bootloader it will warn that installing a custom OS may harm your device. Ignore this and press the home button.
5. You will see a few different barcodes and numbers. Copy down the ones labelled S/N (or SN) and IEMI.
6. Now, press home again and stay in the bootloader. Copy down the model number of your phone displayed in the top left corner of the screen.
7. Smart switch will not recognize the phone, but it will still work.
8. In smart switch, click more, then Emergency Software Recovery and Initialization.
9. Where it says Model name, type in your model number. (Ex. SM-G935A)
10. Click search, then type in the S/N or SN number that you copied down from before.
11. Click OK, and when the dialog window comes up, click ok again.
12. A dialog box will appear that shows what is going to be installed on your phone. Click OK.
13. Yet another dialog box will appear telling you to enter the bootloader. If the OK is grayed out double check that your device is plugged into your computer. If it is not, plug it in. If it is, unplug it from your computer and plug it back in. The drivers may install, but eventually the OK will turn blue.
14. Click Ok. It will download the required firmware. This may take some time. DO NOT UNPLUG YOUR DEVICE.
15. When it is done downloading it will flash onto your device.
16. Your device will restart after flashing and the boot will take some time.
Your phone will be factory restored during this process. If it doesn't work follow the steps again but very carefully. Here is a video that you can use to help you out:
I will not accept any money that you offer me as I have been through this situation before and I understand the struggle and stress that it may cause.
TomatoesOnBluRay
Click to expand...
Click to collapse
first of all thank you!
for some reason i cant get over 11 (after i press ok the first time the smartswitch just closed)
what am i doing wrong?

ofir001 said:
first of all thank you!
for some reason i cant get over 11 (after i press ok the first time the smartswitch just closed)
what am i doing wrong?
Click to expand...
Click to collapse
Im not exactly sure what you're doing wrong. Refer to the video I linked at the bottom if you are having any issues.

I have the same problem I can't get over 11 (after i press ok the first time the smartswitch just closed). I have tried removing and reinstalling smart switch but it does the same thing.

Take it to get reflashed at best buy, talk to the samsung rep there.

Sprint Samsung Galaxy SM-G950U sucessfully unlocked

Hi you all for those trying to unlock and root the Samsung Galaxy S8 SM-G950U snapdragon locked for USA sprint company. Voila! it is possible even if you got the 6th version firmware (latest update to October 28, 2019)
After some days trying to root and lock unsuccessfully and looking info I gave a shot to movical wesite. Price is very cheap and they guide you into the process. Basically the steps are:
1- download and run unlock client software and select your model. (They send you all the links)
2- Select you phone model and Insert the license provided by movical website in the search bar.
3- Install samsung drivers into the pc and connect the phone via usb to pc
4- Open the device manager (window+x ) and see what type of connection is showing the phone. If it say "modem" it will no work. You must set up to "ADB" for that follow this step (two options):
First developer option must be activated
4.1 Dial *#0808# if this not work (in my case didn't) then
4.2 Dial ##3434# when prompted select CMDA, another screen will show up, then tap on DM+MODEM+ADB.
4.3 Check again device manager after plug the phone again into pc it should now say "ADB"
5- Run Unlock client set up the settings and it will return a message that is not possible unlock cause flash must be done first and the software provide the link to download the files needed for make the flash
6- Flashing:
Open Odin and set up the file recomended by unlock client software on the Odin ( i used v3.13 version) AP section. Let Odin software do the rest. Voila you phone has been flashed.
7- After flashed turn on the phone and plug it again into the pc
6- Set up and Run the Unlock client software again and voila this time the software is able to unlock the phone the message " Unlocked" should be displayed on the screen.
8- Recover to stock room
8.1 Download the files recomended by unlock client for recovery
8.2 Open Odin and set up all the files Ap, BL, CP, CSC (you got two option here if you select CSC home yo got the sprint logo back if you dont want it then select CSC file) and USER Data
8.3 Let odin do the rest and check if it pass
9 Voila phone unlocked
I used window 10 computer. As a reminder i did it for Samsung Galaxy S8 SM-G950U with the 6th version of firmware unlocked by Sprint

MDM Locked Galaxy Tab A

I have a Samsung Galaxy Tab A (2020, SN-T307U) that I got from work. It's an old Doordash tablet that Doordash didn't want back, so I'm trying to reset it and it's driving me crazy. I have followed so many tutorials trying to get this thing to work, I keep getting caught on something.
- Simply factory resetting does not work, gives an error that MDM does not allow it.
- I cannot put in the wrong password 15 times to factory reset, even though I get a warning it just lets me continue trying after 15 fails.
- I cannot enter the bootloader, rebooting to bootloader just reboots to the OS.
- I cannot enter safemode, same as above.
- I cannot enable developer options, so no OEM unlock or USB debugging. Tapping build number gives me an error that the MDM does not allow this option.
The device is recognized by Odin, can I just brick this thing and repartition from scratch? Can someone who knows what they're talking about walk me through that? I'm not really sure what I'm doing here, learning as I go over these last 2 days.

Hello,
I have the same exact same issue, have you been able to unlock it?
Thank you!

I can fix it remotely the last hope

Same Issue here,

Any one had any luck with MDM T307U. Please assist.

rittnerb said:
I have a Samsung Galaxy Tab A (2020, SN-T307U) that I got from work. It's an old Doordash tablet that Doordash didn't want back, so I'm trying to reset it and it's driving me crazy. I have followed so many tutorials trying to get this thing to work, I keep getting caught on something.
- Simply factory resetting does not work, gives an error that MDM does not allow it.
- I cannot put in the wrong password 15 times to factory reset, even though I get a warning it just lets me continue trying after 15 fails.
- I cannot enter the bootloader, rebooting to bootloader just reboots to the OS.
- I cannot enter safemode, same as above.
- I cannot enable developer options, so no OEM unlock or USB debugging. Tapping build number gives me an error that the MDM does not allow this option.
The device is recognized by Odin, can I just brick this thing and repartition from scratch? Can someone who knows what they're talking about walk me through that? I'm not really sure what I'm doing here, learning as I go over these last 2 days.
Click to expand...
Click to collapse
If you look at all of the previous post, it should tell you that no one has found a way to disable an MDM lock. Which is as it should be. Otherwise the lock would be useless.

lewmur said:
If you look at all of the previous post, it should tell you that no one has found a way to disable an MDM lock. Which is as it should be. Otherwise the lock would be useless.
Click to expand...
Click to collapse
That's not true as of today's date. (In the event this post is viewed after this exploit can be successful).
I am not taking credit and perhaps the op has discovered it. Anyway...
I am in Canada and noticed the carriers here stop at BL 8 while the USA has BL 9.
The unit i had was on BL 9 (csc TMB).
This probably works for Canadians on BL 8. I don't recommend flashing to BL 9 as that may affect your service or experience.
ANYWAY! This guide won't explain any prerequisites. They are adb, installing unsigned drivers, and you aren't able to use the device and are the owner
1) if not already, power off device with vol down+power and ensure battery is at least 50%.
2) enter recovery and factory reset. If you're having difficulty entering recovery, plug into your pc and as soon as you hear the audible disconnect, switch to vol up+power. Or jam on all three buttons for dl mode.
If in dl mode you can check firmware version and just flash it with bl, ap, cp and csc (NOT home csc). Use exact current version. Don't worry about userdata if it is USA
3) at welcome, connect wifi and imnediately go back to first screen. Don't use data sim
4) dl samfw app and on misc tab, check driver status and your pc will reboot.
*you must not have secure boot enabled
5) plug phone into pc. In the app, mtp and select youtube. If done right, click the pop up on your phone and navigate to chrome. Should be automatic.
6) search for vnrom frp. Once there download package disabler pro and notification app. They are side by side. Install notification app and set it up so you can swipe quick settings from top of screen.
5) unplug your phone from pc and plug it back in. Should be able to get back to the package app various ways to install it. Before install, turn wifi off. Now run package disabler and when it prompts for device admin, turn wifi on. It'll glitch a bit but should start.
6) locate samsung setup wizard. Don't confuse with the other. It'll have a green icon. Disable it and clear the storage. At bottom left, tap the back arrow and you should be back at final setup.
7) when asked to add samsung account, turn off wifi. Complete setup and don't add any accounts.
8) you should arrive at home screen. Your phone is re-plugged right? Good. Now turn on usb debugging and use the remove knox from the app. Done.
*i think i turned wifi on just before enabling debugging. I forget.
*if you are sloppy... you'll need to start over. You'll see, or already know
*you can do ota (if there still is any) but factory resetting or odin flashing will put you back to managed.

mindlery said:
That's not true as of today's date. (In the event this post is viewed after this exploit can be successful).
I am not taking credit and perhaps the op has discovered it. Anyway...
I am in Canada and noticed the carriers here stop at BL 8 while the USA has BL 9.
The unit i had was on BL 9 (csc TMB).
This probably works for Canadians on BL 8. I don't recommend flashing to BL 9 as that may affect your service or experience.
ANYWAY! This guide won't explain any prerequisites. They are adb, installing unsigned drivers, and you aren't able to use the device and are the owner
1) if not already, power off device with vol down+power and ensure battery is at least 50%.
2) enter recovery and factory reset. If you're having difficulty entering recovery, plug into your pc and as soon as you hear the audible disconnect, switch to vol up+power. Or jam on all three buttons for dl mode.
If in dl mode you can check firmware version and just flash it with bl, ap, cp and csc (NOT home csc). Use exact current version. Don't worry about userdata if it is USA
3) at welcome, connect wifi and imnediately go back to first screen. Don't use data sim
4) dl samfw app and on misc tab, check driver status and your pc will reboot.
*you must not have secure boot enabled
5) plug phone into pc. In the app, mtp and select youtube. If done right, click the pop up on your phone and navigate to chrome. Should be automatic.
6) search for vnrom frp. Once there download package disabler pro and notification app. They are side by side. Install notification app and set it up so you can swipe quick settings from top of screen.
5) unplug your phone from pc and plug it back in. Should be able to get back to the package app various ways to install it. Before install, turn wifi off. Now run package disabler and when it prompts for device admin, turn wifi on. It'll glitch a bit but should start.
6) locate samsung setup wizard. Don't confuse with the other. It'll have a green icon. Disable it and clear the storage. At bottom left, tap the back arrow and you should be back at final setup.
7) when asked to add samsung account, turn off wifi. Complete setup and don't add any accounts.
8) you should arrive at home screen. Your phone is re-plugged right? Good. Now turn on usb debugging and use the remove knox from the app. Done.
*i think i turned wifi on just before enabling debugging. I forget.
*if you are sloppy... you'll need to start over. You'll see, or already know
*you can do ota (if there still is any) but factory resetting or odin flashing will put you back to managed.
Click to expand...
Click to collapse
This method works up to step 7 for me. I can't seem to enable usb debugging before knox kicks in. With or without wifi. I'm experimenting to see if I can get past that step.

How to Remove MDM Control from Android?​For anyone suffering from this issue, the following are the steps to bypass Samsung Knox factory reset protection:
First of all, create a password for the device.
Make sure that your device is charged to an 80% or greater charge.
Next, you’ll need to go to Settings and Security Encrypt Device tabs respectively.
Set a PIN/password for your device.
After you have secured your device and it’s gone through. Reboot the device, and when it boots, it will ask you to enter a password in order to access your device to view encrypted data. If you type the wrong password 15-20 times (it depends on your device), it’ll wipe your device of any information and will restart and then appear like you’re registering as a brand new device after a factory reset.

Thats the 2th!!! Try it
Video - Samsung SM-T307U Galaxy Tab A 8.4 2020 Knox Remove || Tab a 8.0 MDM Remove
the Tool from the Video Tutorial is here >> SamFwToolSetup_4.3