[Samsung Galaxy S20 / S20+ / S20 Ultra Questions & ] sanfranguy06:
Long and sordid tale, but here I go (apologies in advance for length):

* 2 weeks ago an OTA update was available and I initiated the download and update right before going to sleep. I wake up to a blue screen that says unauthorized software had been flashed and I'd need to take the phone to the carrier and could be charged for repair

* Completely uninitiated to ROM flashing, after googling, downloading Odin 3.14.1B (patched) and 3.14.4 along with the latest Tmobile firmware, I try to no avail to get the firmware flashed. I figure it's because I don't have USB debugging selected and have no way to get to the option. Holding the up volume and Bixby keys could not get me to the bootloader either. By chance try to restart the phone one last time and boom, it works!

* I enable USB debugging, I back everything up. Everything seems fine. A week goes by, I'm working in an app, it hard freezes, and in trying to restart it happens again.

* Luckily, I still have everything I downloaded, and this time it was a quick task to flash the firmware and get everything working again. Post flash, the bootloader worked and I took the opportunity to clear the cache. I thought I finally cleared out whatever problem I was having with a clean download and cleared cache.

* Another week passes and tonight, same thing. Working in an app, freeze, restart, and blue screen. Frustrated, but I knew the fix. I attempted the same thing, but Odin 3.14.1B hangs at initializing for 30 min. I stupidly disconnect the phone and close Odin with the intent of starting the process over. Now I can't even get to the download screen or bootloader and a new error message reads: "An error has occurred while updating the device software. Use the Emergency recovery function in the Smart Switch PC software."

* Smart Switch does not recognize a device and in attempting the recovery option there are no devices listed.

* In googling, I've found that if I immediately hold the up and down volume buttons right after restarting, my pc recognizes the device and Odin shows it as being added. I try flashing using the same ROM (G986USQU1ATCU), it gets pretty far and I'm encouraged, but then I get the following FAIL error:

<ID:0/003> Odin engine v(ID:3.1401)..

<ID:0/003> File analysis..

<ID:0/003> skip file list for home binary

<ID:0/003> quest.fv

<ID:0/003> testvector.fv

<ID:0/003> spunvm.bin

<ID:0/003> persist.img

<ID:0/003> carrier.img

<ID:0/003> dqmdbg.img

<ID:0/003> userdata.img

<ID:0/003> metadata.img

<ID:0/003> misc.bin

<ID:0/003> Home Binary Download

<ID:0/003> Total Binary size: 8868 M

<ID:0/003> SetupConnection..

<ID:0/003> Initialzation..

<ID:0/003> Get PIT for mapping..

<ID:0/003> Firmware update start..

<ID:0/003> NAND Write Start!!

<ID:0/003> SingleDownload.

<ID:0/003> abl.elf

<ID:0/003> xbl.elf

<ID:0/003> xbl_config.elf

<ID:0/003> tz.mbn

<ID:0/003> hyp.mbn

<ID:0/003> devcfg.mbn

<ID:0/003> aop.mbn

<ID:0/003> cmnlib.mbn

<ID:0/003> cmnlib64.mbn

<ID:0/003> qupv3fw.elf

<ID:0/003> NON-HLOS.bin

<ID:0/003> dspso.bin

<ID:0/003> km4.mbn

<ID:0/003> storsec.mbn

<ID:0/003> sec.elf

<ID:0/003> bksecapp.mbn

<ID:0/003> tz_iccc.mbn

<ID:0/003> tz_hdm.mbn

<ID:0/003> apdp.mbn

<ID:0/003> msadp.mbn

<ID:0/003> uefi_sec.mbn

<ID:0/003> multi_image.mbn

<ID:0/003> vbmeta.img

<ID:0/003> vaultkeeper.mbn

<ID:0/003> boot.img

<ID:0/003> recovery.img

<ID:0/003> super.img

<ID:0/003> dtbo.img

<ID:0/003> FAIL! (Auth)

<ID:0/003>

<ID:0/003> Complete(Write) operation failed.

<OSM> All threads completed. (succeed 0 / failed 1)

And a message in red letters on the phone appears at the top left that reads: SECURE CHECK FAIL : super Image Extract failed. Googling this returns nothing.

* I download Android SDK along with tools package to try and start the phone in download mode to flash, but typing ADB Devices in the command line shows a blank "List of devices attached", even after killing and restarting the ADB server. I see "Samsung Mobile USB CDC Composite Device" in my computer's device list and this is the most updated driver. Attempting to load legacy Android ADB interface, Android composite ADB interface, or Samsung Android ADB interface results in an unrecognized device and still ADB Devices does not show any results. Dead end.

Having spent the last 8 hours on this, I'm at wits end. This may be the last time I purchase an Android device! Simply ridiculous that something like this could happen. I'm not reading the same problem anywhere else so it sounds like it's just me so possibly some sort of lemon.

Can anyone please help me? I'm really stuck and would be super appreciative. Thanks in advance!!