[Samsung Galaxy Note 20 Ultra Guides, News, & Discu] mellojosh:
Hello All,

Many people have asked about service mode and CSC related questions and I thought we should get a discussion going that is all in one place.

*DISCLAIMER* I do not take any responsibility for any issues that may occur from changing settings in these screens. They have the potential to cause service or data lost if used incorrectly. You have been warned!

Service Mode Guide

Access Service Mode

To access service mode screen, first download the Google Phone App from the Play Store (Phone by Google-Caller ID & Spam Protection is the official Play Store Name)

After installing the phone app, open it up and select set as default *Note* You will only need the Google phone app to access service mode-Once all the changes are made you can keep using it or change back to what you were using*

Another pop-up will show and select the Phone (blue icon) and set as default. Go to the dial pad icon in the bottom right corner and dial the following:

*#*#27663368378#*#*

When you dial the last * in the string above, the service mode menu will automatically show. YOU SHOULD NOT HAVE TO HIT THE CALL ICON BUTTON TO MAKE A CALL AT ANY POINT.

[IMG="Service Mode Main"]https://lh3.googleusercontent.com/GEtmxR5J-vLwrxtogkVOn01je_6Lch2EYPQxJyU6IiCNwyTJFpjO2A4dRkFo68KPtD0zfV4O4_gAj-QXbWbmLbmsIEeHn8nNRhvEM-v6SJXhS2X1x4lPFZD1-Xsvrf2th1nmMxwaXVBwtJ5n6yOBzlJRGvwIC1ev-Ty0VXTcTyy00OuTUaBzLs-7TJEqNFUh-M117UN9q0Pu3i3csDxjRdNV0fN3zw4eT2WRogZcG3JrrimHnUZEPa9seBdvU9NOarASEZYWEWIMc1-ko9vaXlnNjJUuhPiNnSxXOwPyKK_pLdar0OSzOXgwsaWFPm3sJ-qLZjQc3EP-NDqg_n2qyUCaeamVnPf16_Rxjxwmu1GRSYLOzqwBlg0GjpncgqdeDPXP-Dn2QcHlSgmaATEH_vArZOsdMY8PW8MmbVA4IpwmhFy2pGqb-iNIh6SLlWlHDEpGqrHCZhWMMeF9Nq83-4H6uo3QDAdXuyHkEYB7c7Cu6_DmzsmUUClbq5XgqDzsYrRj23ed6d1pV0_yUvqTCWkWKpqaw2TpJjlafdfbXCrOdKUxSBW-tZ-JLjOgFPpqcRRj11-jgMNy9Rg5NcWJsXV2NGbeMFQQAFa4Rsty2E2q5z1JpQiRXbrzn5lWlGwKAkYBb8IlwRBCEzVmjJIay_VOLDvbYYrGHaqyT5JRssv-SDjPxOqhIYVQA82Z=w373-h800-no?authuser=0[/IMG].

Congrats, you are now in the service mode menu!

Enable all LTE and 5G Bands

*NOTE* Remember whenever navigating through the menus that the android back button on your device will automatically exit you back to the dialer. To go back, you must use the 3 dots menu at the top and select Back.

To enable all the LTE Bands go to:

1-Option 2-UE Setting and Info

2-Option 1-Setting

3-Option 2-System

4-Option 9-Next Page

5-Option 9-Next Page

6-Option 9-Next Page

7-Option 9-Next Page

8-Option 1-Set LTE Band Config

9-Option 1-Set Default LTE Band

This should enable all the LTE Bands for the country that the firmware installed is from and the available roaming bands that are set in the firmware.

For the 5G Bands go back (using the 3 dots in the top) until you see UE setting menu and the 2 options for Protocol and System then:

1-Option 1-Protocol

2-Option 9-NR5G

4-Option 3-NR5G Prune Status

Here you will see a [1] Remove NR5G PRUNE option as the last line. Select that option. If you visit this menu later, it will show a * next to NR5G PRUNE is Removed and the option will change to [1] Restore NR5G PRUNE, in case you want to go back.

Enable DSS

Now that all the bands are enabled, you have to enable the DSS setting. Get back to UE SETTING MENU with Protocol and System options and:

1-Option 1-Protocol

2-Option 1-AS

3-Option 9-Next Page

4-Option 9-Next Page

5-Option 2-NR DSS CONTROL

6-Option 1-NR DSS ENABLE

Just reboot the phone after this and this should be all that is needed to enable all LTE and 5G Bands and DSS!

You can then go back into the Google dialer and dial *#*#2263#*#* and this screen will pop:

[IMG="Band Selection Menu"]https://lh3.googleusercontent.com/g23W28hUIrJQHoFhP371hn1XQCK_w3b9JCOxfOL-bbhSB59PcquenA81d6n-O0HVtLbWbl3jMOgOSacBvtO5bFkpgzjIwMuRpeWntB8tt6xbOajvVxGILaaS_lrhvwlwC6EFC9sBZJsCqKIWTV4ZzEe27mVC6N87ghDJdTI6Ho6SdACNub_PC2Cey1EN8c6wdp96yckcA-C2b7MGZnrplsXHmslJOs0HDU1CO8uxdggQ6xKS5y4SVp0Xz80qsEpVhpakBC173cWSxPsuKS0LUQNgmvVcsA4NakqDSMaeI3luoI_2cpOn52B6k0TCZQOROYdDrT51mb1PXmP3Rk0V1F_lvqn-Yw6t0qrxXHoF1mDjw0fAeFRtQsS2SwbrV5Cbmuc-S5XGbWtiBQ9eTp6c3eXN7y2VtQHTgAcVyd54q0TZXALpPYb9l6vEkqBOejVbuAaGqAQFwRjJY-XEoQss1n_zNcQIVYLq8XSK9s80AlNB8ZG7zXJJk1EdnEcDpe9w--idATqW8AjC8-ZEtevgfvrAdaiZsEgbKSjQ3cQOS9rOsekqG3grAl0jb5jkHTcNw4BoIV4rDG2QYV-2bAH1-tpiwcNXN63izIYcykfMnvMHa9oqr68eN77G96WjMG6U7VcnQMsz26J-55MbHYshBSdkIua8Nk14tqhTyXLc1KmgyNzomCw05REvmmJB=w373-h800-no?authuser=0[/IMG]

CSC Guide

CSC (which I think means Carrier Service Code) helps to set what options for settings show in the device for things like voicemail and wifi calling, as well as sets network code information for things like carrier aggregation combos.

When you go to your phone settings->about phone->software information and look in the Service Provider SW ver. section, you will see as the last line a combo like XXX/YYY/ZZZ. This indicates what carrier sales and network code is set and what brand the phone was manufactured as.

I think of the XXX/YYY/ZZZ configuration as follows

XXX=Sales Code-What kind of features are setup in the firmware like wifi calling, video calling and settings menus

YYY=Network Code-What kind of network features are set for things like carrier aggregation and LTE/5G bands

ZZZ=Manufactured as Code- What model the phone was originally manufactured as. Ot has no affect on the system settings or options. THIS CAN NOT CHANGE. IT SHOULD ALWAYS BE THE SAME. ONLY A ROOTED PHONE WOULD BE ABLE TO ACCESS THE FILES NECCESSARY TO CHANGE THIS.

For the Example of VZW/VZW/XAA, this would mean that the phone was sold as unlocked from Samsung and has a VZW SIM in it, setting the sales and network codes to VZW (XXX and YYY should usually be the same since you want the Network setup to match the settings setup in the phone, but they can be different, especially if you try to change the CSC in the U carrier branded firmware.)

Changing CSC

*NOTE*Changing the CSC does not necessarily need the Google phone dialer like for the service menu, however, if you are on a CSC where the stock dialer does not provide you with the CSC change screen (Like when your code is XAA/XAA/XAA) you can attempt it through there and see if you can access it. I haven't been able to test this yet, so let me know.

First, go to settings->about phone and at the top you will see your IMEI. Press and hold on the IMEI number and you will get a popup saying copied to clipboard. Then, go to the phone dialer and dial:

*#272*

After you see the numbers dialed at the top, press and hold after the last * and select paste then dial #. Again, you should never have to actually press the call button. A screen will auto pop. If it does not, try the Google dialer.

[IMG="CSC Selection Screen"]https://lh3.googleusercontent.com/Zhs2G-GcSTO6ksWLj_4WmQeqBzyN1NBQPM2whbwJKbygN0WbeqJkR_cTZvCQ_wrHknIDwVrp8MI6vIYVwiVCpnT4xr6R48JXd4UtCe1M5eV67eQDZF7kBoY_smYhUYLocbxuu-WQaePyZJW4nL7VCKNJ0ONjFpgffGNpgK2PCoRpccgSGcJ7BMGuYXBR3YqzjzPGD-p8JzEnYPWcILpFYXBvUopsedGhUQsvmrj_HYGGP9J8C3gc_zU3xLw48aQoAtne2c0vfkQf9tDG2I5UsyA4tU0MAsAdnDEEoIBjthW0W86UQ57mWA17NCxjZU0zOZ1I8_wdbz5YjGwAVWkA7Ungko9BSFOllcKxjvIG9N9lKjFm6zOtEjpdvGNReP7WpL0tL_C3x6Tgc_Qs5VLTGpr7ZKYld5q6_i13XsLI6V9ctUH8d7nDXrvPIuhvBWaerBb6tabxb_OnOli_El3LHcsUq-iVfGDP9zxWEHkft_BDxvG6zkv5BaZAR-g55tAur-HHUuReJ_vLt9nXLO7pNMVLzAkF4FkvjgW2hgqowXCvunCMuGl_90hZlWCGLVnXQH9B7p5eaMfrJwVjDdwXy6whiIukizfW7PDltFxqVF0imAD4eFDNm-HAxOAeVz_b1lmMHOftRL9ze_hHu0eE-v9ea0V0xCqIVPfskOyve7KSt5tKa5UyktPWZGHw=w373-h800-no?authuser=0[/IMG]

*Pro Tip*

Since some CSCs do not allow dialing the IMEI (like the XAA CSC) I recommend after you get to this screen to first select the recent menus button on your phone and click on the CSC app icon in the mini view. But beware, this is not working in the One UI 3 beta!!

[IMG="CSC View"]https://lh3.googleusercontent.com/WWLUpYTaf2havLIVpFl1sPgVx929cLvK62tGuLVVCBcM0h0cc46EFX_ox5y3EsQsasf4GqsnunYuec_nG9iO3YvxLXeSxBp_n_YnL67Hk6gteXwqBWXD3-xWydtcbOz_jS5YzSnTUhnUGAsRBZzT_QxKZWe3jih3Mqlib7-5LwWLAMSOinOqexDsN_Kl9vwyHP8ZK2JGz9FKp7oAXuenDijy2yfqairzVNApqlsX4JU-kMFoEYHkdNDQvLSHjT1je230mRn5BCCKhN_RAQgbu6_bSgHRY16BfdqudV6GJUrJ5RqRL1g4y_63cxB3x3l55QioPFPGnI16ZhQgxGjLqeHSa1wLMP6p6pCiwX7UoBS9r9ytJp05Wi7_Y2PB7b4vHVWRvxVlftIjwA0KdNTGjS__EErLytBK3WKlC3mI3qUq84LMCT5LIGfZL4NtHJYXgg0MrBAgM5E8rc7-2XIXMQcHw97WXALbu6SF1PGKf2ZdJcRVOrRwZbYCEud9R6iyVSJPLh2HFjjqbLOfBMouN5cJ78FjN9WKJtmOjpMkffKxHUuCID5DQiYz8liSBG1mTnu-fQXQBmld-cxuk2ABqUcf6FKNizuKexyjMA_BlmqTmmCXpJhM7qfLCjxMR0QloD55dxfJX18svhl4J9LiTKHPr6K-kovflgnLT-ws1-hHTwad2pJIqqXvFRgF=w373-h800-no?authuser=0[/IMG]

Then click on Keep Open for Quick Launching

[IMG="CSC Keep"]https://lh3.googleusercontent.com/XkA07c7Yvt-V5nI-DQmWsNwsYQCJNkpe2QkfoUsWTbKv-x-0CXiX7JCC5zRaX5thnP1Xwz1o2VCmn-PEC1sWu7tdUDox7vXQKAMdjWiR448ESqm8Fy4YUK7awTJWMUTitPMuuv0UM9ZApsHDWoKWT5y4NibjijnosXbwSdqu3LrDWD6bkEFNklk2tKIr4G03JXKtS-rLMz7av79fh-Z5BDJnjDwJr06bRcN9znjUGsjhHI8KU47yljIcRIkY2Y_MxnJHAtG-vvQmPxRQmrRvIJiD7kkHqOA6T7TGb3dRiJZAqPo8BFqjAl_939foy3P6oFrZsdhWueO7M-oh3BUCDis4iao7-IjlUdg2wiQS8vfEtOTeFdlNKrX7njgiv3hhoQNzsP-E8PHJAD-qNiuhgJxq557KtfASYQodGMvUXGqzNLI9pBqw6NZypF0nQYcQRjY4lB_gfREmd4yHreWMJhrMcUe392Tj0sC6AFowhpKMU4hvK9Pc1nihTbYsFd5dVAA_TT4CcXvOIwsXl6W45MuGiESv1uv0sMv26zJz9GfuSlQdO4BZj2mjTgnzsd1IyMTX5yeOMKvwinhEyq4hPsA-Lyu72cCMwfdduCBbck6VV_78eJB_w37MXmC2EwkJClRgx4e32jerCioSzvX20ePR0OrP25aGr_k9I-qMvxaQIPT10ef_4GFhizva=w373-h800-no?authuser=0[/IMG]

Then you will have a lock at the bottom of that apps recent screen to show it will stay in recent menu, even after reboot and selecting close all apps button

[IMG="CSC Lock"]https://lh3.googleusercontent.com/UfrVLrRCcoUCsZ9ioSBTg0QijNg8zrAqlxHIJ3uZDGQKR6CYNTyofN16j9MChBv_m0lTYd6HYGwVMAkAQcYED0nKC-I6gYivb-prgBlu5qCQn8nJ_Es8i2FtW3uJwE-2ltIiFtfR0Ky1t2Z0dGIcDRGnDfwU-M5VTFwh5rS8n83axjMbDKbNIp89H3RzTuRLzfy7RrlpocLKDCODYLPPGu7kMhUTuYJLExMmWR1LFg16rmfeQfCt4LFUj4uZRo6GncaBIAN8MCJp_hoEAPfLIMElxYzp2GWGZO6fGZF0-qeksu75qTiEJss5YpzFCV0SVsiEAV3f_fR7FiMk6L2p90-dn_mDiO4U8K4lfgP8kFnLeQqLjJoSHxV4wT7VhcHF7IFnxm1QKL8sjHzgcZO_MYGQGWXi5c9TJaFG4HI6tMMMe-IItjz_GR5VQyoTxO4N5kpVAAYqn2E1pRXpD5dBoFqqjGOwXQ8QcprEPZMZJZ8xQB_bwQbTJKjn2DtUIiHY3lroLF3n36E5b14ldHrR07j17qq3PmqYi29YnfTTgm-J_nqPzIf3EDqQoYuGfag4VeZVOiB529Fd-WCGevnq9fGGnpDfqkPh2ueKbE5D45f-PRKcRB2e3dMqKvOQ1J9roK6WndJ35gglPORX94X7C7h931e6eoTRnUDqtDNqbkUutC0Z48S_NnzUAszc=w373-h800-no?authuser=0[/IMG]

As you can see, mine is selected to VZW/VZW which is the XXX/YYY portion of the XXX/YYY/ZZZ combo (again, ZZZ should not change. Only having root can change this!)

You can now select a CSC and then click install at the bottom. This will reboot the phone and should not wipe any data.

*Pro Tip*

At the bottom of the CSC screen, there is an option that says Don't change carrier(for DEV/QA). Well, you know how when you change the SIM on the U1 firmware, the phone detects and new SIM and reboots to apply the new carrier settings? You can choose this and select install and get a popup showing ENABLED and the phone won't reboot, allowing you to choose the CSC and keep it with whatever SIM is installed.

[IMG="MPS"]https://lh3.googleusercontent.com/SRRgdfXbgVrlX0gi39nrNvCOP5fUpxpsFwx07Uizs4rArx-_Os2b5uiqVeDLnYEQF41bX5NGF4wAWvIt47XdYB5hpIiIgVDqf-Ke7YLX4UhhSDwOjsD8s-jAm1B6uCUw0RS8Fqq1MMH8k9yGZ_EalB5aT1AFCdF1NQjObWcz-is4vo4Cw_PqVdNVvs2zNA70lelgxoBaoLEcqPgATGtWDqj-OyUMInPsXuAEvYrYSgFJmi24zqxTKxbGOPJLyX_xtYBKgcq-EM8fDavpsWdwfAXKG-h9HpaGjeAJU0kBpyvCS_Bpr1BQrS434VWANjlGgK_oXM56Elzv9X9-AMplSVerXoGXZHi95csmxfJS4y1GCBpYv0uOkCc-ptlI9eW7keuRPSlvir0al1RVrAUn8lLQkGKU4nwS3zhoP61qx8cShoLumwqLKX9gJd4RBEb3YhxGu_iaP4MHOAgXlAgQSkNCcRNDDOoIRkd1EbdtHb91oe2IFWBxObET7nhzlksWzEQWyHVdZ06XkKLokjjiTEpzZk3gzDbnRA46HTazxsGe4KvD2s4YSZqZbMUMxhpyB7u2j3WIyJLsYTx5ledUzfLae5r0suTB7uraTAHVRS4n82NfwdvrbvTgeJL_G9f6rSVKKd0h8Srhb8vjbygcvJzzxHn2t2BE_aleUxsmE4NZNI8mQW5FJr00UmQS=w373-h800-no?authuser=0[/IMG]

Here is a list of the available CSCs on the U1 and the Carriers I have found:

ACG=NexTech/C-Spire

ATT=AT&T

AIO=Cricket

LRA=Bluegrass Cellular (possibly other smaller carriers also)

VZW=Verizon

BST=Boost Mobile

TMB=Tmobile

TMK=MetroPCS

TFN=Tracfone

USC=U.S. Cellular

XAA=Unlocked Non-Branded (Google FI is an example)

XAR=Cellular South

XAS=Samsung Unbranded Sprint

CCT=Xfinity Mobile

CHA=Spectrum (Charter)

XAG=Some MVNOs that use TMO, like Mint (confirmation needed)

ATC=Unknown

FKR=Unknown

GCF=Global Certification Forum

WWD=World Wide Device

SPR=Sprint

DSH=Dish Network

I hope everyone finds this guide helpful and I will add/change any information as it is discovered.