[Guide] Service Mode and CSC Guide/Enable LTE/5G Bands and Services/5G Low Band on U1

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Senior Member
Aug 12, 2013
any update? the step for unlocking all LTE and 5g bands not working anymore on my latest May security patch for s20 canadian version, it just unlock LTE bands only but not 5G bands.


New member
Jul 28, 2020
Hey, If! are you familiar with the efs file explorer...? Or QPST. I found out how to get it mmWave back working


Use this file... Save it to your phone... Remove the (.bin)... Transfer to your computer... Use efs... Go to /nv/item_files/rfnv/

Copy the file here
When you download the file it comes with (.bin)... Remove that from the name
Then save it to your computer
Once you save it to your phone using efs explorer, power down your phone and then go to the Samsung secret menu and enable all the bands like normal,

Thank to u/VincentMartel007 from reddit!


Senior Member
Dec 7, 2009

is there a way we can send AT command or other cmd to automate or pull the data out of the phone to a txt file?

i just want to query RX RSRP value and record them to a TXT file in an automated fasion.

Is this possible?
Hello, I have the Note 20 Ultra 5G (SM-N9860), I have the VOLTE option enabled but it does not appear near the networks icon as I see it on other smartphones. Does anyone know if it's really activate or not?


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Hello, I have the Note 20 Ultra 5G (SM-N9860), I have the VOLTE option enabled but it does not appear near the networks icon as I see it on other smartphones. Does anyone know if it's really activate or not?
I have VOLTE showing with my EE network in the UK when out and about, but not whilst at home with WiFi Calling active.
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Excuse my ignorance as I'm not super familiar yet with 5g, but I currently have the 986U on AT&T and am looking to get an unlocked U1 device instead (switching from FirstNet to regular AT&T). I know by default the U1 doesn't support NR from what I've read, will this allow me to enable 5g NR on AT&T with an unlocked device, or should I just stick with the U if I want to retain that feature?


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New member
Aug 16, 2021
Hi all, i have a samsung s21 with exynos chipset. And i am trying to use it in a 5G Stand Alone network. I've tried the codes mentioned in this thread but as soon as i put the last # the screen just turns white. I would like to be able to choose NR 5G networks since right now the phone is not working. Do you know if the code is different for the s21 please? Regards


Feb 10, 2021
Hi all, i have a samsung s21 with exynos chipset. And i am trying to use it in a 5G Stand Alone network. I've tried the codes mentioned in this thread but as soon as i put the last # the screen just turns white. I would like to be able to choose NR 5G networks since right now the phone is not working. Do you know if the code is different for the s21 please? Regards
As I know there's no way to get into Service mode on OneUI 3.0+ Exynos phones.
( I have a Note 20 5G N981B/DS and tried lots of ways but no luck. )
If your device is rooted then you can use other app to get into the service mode.

And for the 5G on Exynos devices, make sure your current OMC code includes your region
So you can get 5G connection while the default settings of OMC_BASED_NR_PLMN is Enable.


Senior Member
To those having difficulty with the code on 3.1 - I was able to launch the menu using a terminal editor, but I assume it'll only work for rooted devices. The commands I used:

am broadcast -a android.provider.Telephony.SECRET_CODE -d android_secret_code://IOTHIDDENMENU


New member
Oct 5, 2021
I have just purchased a s21 ultra 5g from the USA (unlocked version) and I'm trying to get the 5g work in the UK on VOXI (Vodafone's low cost network). Following the previous post i've activated the 5g bands but it's missing N78 (the one voxi uses according to their website).

Do you know if Qualcomm x60 has this band and needs to be activated via SW?

I've also found that changing to UK CSC might help. Do you know anything about this. This will factory reset the phone and I'm afraid it will be in vain.


Sep 17, 2018
I got the S20 Plus 5G, Anyway to get to the service menu that *#2263# would open before the 3.1 update? *#0011# will open network info.

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    Just check the code on my N9810 BRI
    This method only works on Qualcomm versions
    I use *#*#276633683782#*#* on Google phone dialer
    and it brings up a service mode screen.

    Press [5] RF Test and choose [2] PREF MODE SET
    (or other options also works )
    It will show Please use *#2263# for mode set
    Then just tap three dots on right top menu and choose back
    It will bring you back to the main menu.

    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:

    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.

    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:

    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:
    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.

    *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!!

    Then click on Keep Open for Quick Launching

    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

    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.

    Here is a list of the available CSCs on the U1 and the Carriers I have found:
    LRA=Bluegrass Cellular (possibly other smaller carriers also)
    BST=Boost Mobile
    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)
    GCF=Global Certification Forum
    WWD=World Wide Device
    DSH=Dish Network

    I hope everyone finds this guide helpful and I will add/change any information as it is discovered.
    Hey guys, I've just activated aggregation and missing LTE bands on Android 11 for Chinese firmware SM-N9860 (Snapdragon) using QSPT & QXDM tools for Windows. No root needed. Instruction looks big but nothing hard. The only issue it is in Russian for now. If you want to try probably have to use Google Translate. Check my post on 4PDA. I don't know if it will work for your device version or not. Please let me know.
    *#*#27663368378#*#* still works for me on TMO N20U (unlocked) after Android 11 update
    but *#272*IMEI# doesn't bring up CSC menu which was available before Android 11 update.
    Following code works to bring up CSC menu.
    Dialed *#*#27262826#*#* on my unlocked Tmobile using google phone app
    *#*#27663368378#*#* doesn’t work on google phone app for me on N20U (unlocked) with ATT CSC after 3.1 update

    *#*#27262826#*#* doesn’t work on google phone app for me on N20U (unlocked) with ATT CSC after 3.1 update

    *#272*iMEI doesn’t work on samsung phone app for me on N20U (unlocked) with ATT CSC after 3.1 update