[Samsung Galaxy Note 20 Ultra Guides, News, & Discu] BlinkThinks:
WARNING: THIS PROCESS WILL RESET YOUR PHONE TO FACTORY STATE. BACKUP YOUR FILES BEFORE YOU PROCEED. YOU MAY DOWNLOAD SAMSUNG SMART SWITCH

HERE

I finally got my CSC back!

What I needed:

1. Official July Security Firmware - Because the CSC Changer will only work if you have a firmware lower than the August Security Firmware

Since I wanted the XTC firmware back, I downloaded the OXM firmware with multi-CSC N986BXXU1ATGI file here Warning, very slow download speed.

Since the security policy for both firmware hasn't changed yet, I was able to downgrade my firmware, from the current one on my phone N986BXX

U1

ATH3 to the older one N986BXX

U1

ATGI

[MENTION=238849]Aresnalove[/MENTION] confirmed that he was able to downgrade from the September patch without issues.

You can use ANY one of these firmware. They're basically 'OXM with multi CSC

MEGA Links:

XTC-N986BXXU1ATGI

INS-N986BXXU1ATGI. Big Thanks to [MENTION=2630529]keieva[/MENTION]

GDRive Link:

XTC-N986BXXU1ATGI

2. CSC Changer App (Windows Installer). Here are additional links containing a compressed format that you can choose from if the first link is not working: 2nd LINK and 3rd LINK. (Disable your antivirus before downloading as it's being tagged as a virus.)

3. Odin 3.14.4 to flash the firmware. (Instructions here, thanks to [MENTION=1586120]henklbr[/MENTION])

What I did:

• Removed my SIM cards from my phone.

• Disabled my antivirus before installing the CSC App changer in Windows.

• Disconnected my PC from the internet.

• Flashed the N986BXXU1ATGI firmware and proceeded with the phone setup without inserting my SIM cards and connecting to the internet.

• Installed the CSC Changer and followed this video - Your phone will update the Store App. You need to connect to the internet temporarily. As soon as the update is

complete, disconnect. The 'theme' should show "Try Now" to work. If you continue to be connected to the internet, it will show "Buy" and it will not work.

• I selected the 'Android 10' option in the Legal setting (You will see 3, one for Android 8, Android 9 and Android 10)

• After selecting my CSC and the phone restarted, I got my CSC back to XTC from DBT where I got stuck :D

• I again flashed my phone to the latest firmware N986BXXU1ATH3.

• Turned back on my PC's antivirus.

• The *#272*IMEI# code works again on my phone on the latest XTC firmware, (see attachment for available CSC codes). Kindly get back and check if this code works after successfully changing your CSC.

TIPS:

• After changing to your choice of CSC, check first if the features that you want are there and working. This will give you another chance to change your CSC using the CSC App changer.

• If you are satisfied with the results, you can then upgrade your phone to the latest Security patch by downloading the file for your phone using Frija and then flash with Odin.

• Some prefer a full reset of their phone, others prefer to keep their files and settings. If you want to keep your files and settings use the HOME_CSC instead.

CAVEAT: This process worked for me. Again, I would like to reiterate that I needed to downgrade my firmware to pre-August 1 Security Upgrade for the CSC app changer to work.

This process will not trip Knox because you are flashing an official firmware and the CSC app did not affect Knox as well. OTA update works. Your chosen CSC will be retained even after an update - unless of course, you decided to change your CSC manually.

I would like to thank @tribalfs for giving me an idea how I could change my CSC, specific for the Exynos version.