[Samsung Galaxy Tab S4 Guides, News, & Discussion] n00_dles:
I'd like to thank you. I've followed your instruction to save my tab (SM-T830 (france)) which was stuck in boot loop :

The boot loop allowed me to enter into stock rom but only for a few seconds before it restarts.

This summer, I solved this issue by flashing again the last stock rom with ODIN in download mode.

It worked a few months then became unusable boot looping again.

This time flashing official firmware didn't helped.

Despite having only few seconds, I've managed to OEM unlock and install lineageOS by following your instructions.

LineageOS was stable and I installed my usual apps without issue. BUT the boot loop has returned when I updated google app!

So I flashed lineage-20.0-20231214-UNOFFICIAL-arm64_bvN.img without google apps and the OS remains rock solid.

The only downside is loosing Widevine L1 by OEM unlocking the bootloader. It seems there is no way to keep L1.

But L3 is fair enough to unbrick the device.

My conclusion is "my" bootloop is probably an hardware issue with some memory or crypto security space used by google safenet, or the like.

I don't know if someone else have stated this elsewhere and found a solution?

I've successfully installed magisk using instructions for samsung devices : https://topjohnwu.github.io/Magisk/install.html#samsung-devices

So I can complete your procedure with extra steps to get Magisk on lineageOS :

1. Prepare patched AP

1a. On PC, download and extract latest firmware for your device.

1b. Transfer AP file to you device

1c. download and open Magisk APP

1d. select Install and point to AP file you've just transfered.

1e. Once finished, transfer patched AP file back to PC (contains patched boot partition as far as i know)

2. Flash patched Magisk firmware

2a. Be sure to OEM unlock in developper settings (if not shown follow the date tricks)

2b. Put the device in download mode ( on recovery bootmanager or "vol+" and "vol-" at powering)

2c. On PC in Odin Options, untick "Auto Reboot" (very important!!!!)

2d. In Odin, flash original BL, new AP, original CSC (and original CP if needed)

The following step is important to avoid to be locked by Samsung RMM (Only official released binaries are allowed to be flashed)

Odin's "Auto Reboot" have been disabled because the first boot need to be in download mode to flash TWRP immediately. If not, samsung rom fist boot will RMM lock the device, and you will need to trigger OEM unlock OFF and ON in stock rom. Just in case : I believe time and date are involved and I've managed to speed the process by flashing previous firmware (plane mode to block updating date) and flashing the last one again.

3. Install TWRP

3a. Download twrp AP_twrp-3.7.0_9-0-gts4lwifi.img.tar

3b. Shut down the device holding "Power"+"vol-" and immediately hold "vol+"+"vol-" to enter in Download mode

3b. untick "Auto reboot" and flash twrp via ODIN in AP

4. Install LineageOS

4a. Shut down the device holding "Power"+"vol-" until entering in twrp (recovery mode)

4b. Keep twrp read only and format data to start without rebooting

4c. Download lineage-20.0-20231214-UNOFFICIAL-arm64_bgN.img or bvN flavor (https://sourceforge.net/projects/andyyan-gsi/files/lineage-20-td/) and Disable_Dm-Verity_ForceEncrypt_11.02.2020

4d. Extract image to your sdcard and insert SD card to the device

4e. In TWRP, choose install, select SDCARD and switch install image and select lineageos. Install to system

4f. Before reboot, install Disable_Dm-Verity_ForceEncrypt_11.02.2020

I'm new to lineageOS and magisk, I've installed it to try to recover HD in streaming apps.

I've installed:

- magisk app and activated zygist in settings

- modules :

- microG installer Revived

- Universal SetyNet Fix

- Zygist - LSPosed with FakeGapps module

- F-droid

- Aurora