Author:
Randy Alexander
Date Of Creation:
24 April 2021
Update Date:
1 July 2024
Content
Do you travel a lot and want to use your phone in another country? Or are you tired of your current service and want to change to a new carrier before your contract expires? Unlocking Samsung phones allows us to use another carrier's SIM and connect to that cellular network. You need to contact your carrier to unlock your phone, but it is still possible that the contract is not due and they do not support. In this case, you can consider using a third-party service or manually unlocking if the phone model is suitable. See step 1 below.
Steps
Method 1 of 4: Contact carrier
Call carrier and ask about unlock policy. Most carriers will agree to unlock it after the user has used the phone for a certain period of time or when the contract expires. If the contract is still in effect then they will likely ask you to pay an early termination fee to unlock the phone.
- They can unlock it early if you explain that you're on a business trip abroad and need to use your phone.
Contact the carrier you plan to change. Many carriers are willing to unlock the phone if you switch from one of their competitors. Call the carrier you want to change and try negotiating if you use their service, will it support unlocking the phone or not.- Make sure that your new service provider is on the same network that your phone supports. In the US, GSM (AT&T, T-Mobile) and CDMA (Sprint, Verizon) are the two main types of networks. In Vietnam, all major carriers (including MobiFone, VinaPhone, Viettel, VietnamMobile) operate the GSM network.
Find the code for your Samsung phone. If the phone has been out for a while then the unlock code is generally provided by the manufacturer. Look for the phone model on the internet to see if it has a code. With newer phone models it will be almost impossible to find the code. advertisement
Method 2 of 4: By paid unlocking service
Find your phone's IMEI / MEID number. You will need to provide this unique identifier when requesting an unlock code. Open the calling application and use the keypad to dial the number *# 06#. The 15-digit code will appear on the screen.- Write down this code so you can easily re-enter it later.
Find a reputable unlocking service. There are many companies out there that claim to be able to unlock phones for a fee. Because you are going to pay to unlock your phone, make sure that the unlocking service is well rated and has a solid guarantee.
Required code. You will be asked to provide your IMEI / MEID number with contact information and payment. The amount payable will depend on the phone model and the speed at which the code is retrieved.
- It can take up to several days to retrieve the code because companies of this type often rely on carrier relationships.
- When entering information of your phone into the service, you need to make sure these parameters are 100% correct to be able to get the code back to the device.
Insert a new SIM card. After receiving the unlock code, power off your phone and take out the SIM card of the old carrier. Then, insert the new carrier's SIM. The SIM tray is usually located behind the battery or on the side of the device.
- See online instructions on how to find and remove a SIM card.
Power on the phone. You will be asked to enter a code to connect your phone to the mobile network. Enter the code you received from the unlocking service.
- You may need to be within the coverage of the new network to request a code to appear. This process will vary by device.
Check if the phone is connected. If the code entered is correct, the phone connects to the new mobile network. If you can't connect to the new network yet, you need to make sure you are in range, then contact your carrier to see if your phone is unlocked properly. advertisement
Method 3 of 4: Unlock Samsung Galaxy S3 and Note 2 manually
Make sure your phone is up to date. Phones need to run Android 4.1.1 or higher to apply this method. You can check your device's version by opening the Settings section, scrolling down to the bottom, and selecting About Device. The version will display below the Android Version heading.
- To update your phone, open Settings and scroll down to the About Device section. On the next menu, select System Updates and click Check for Updates. The phone searches for the available updates, and if any, the system downloads and installs automatically.
- This method is not applicable to devices with a custom ROM preinstalled.
Open the calling app. You need to enter a code in the dialer to open the Service menu. Once the dialer opens, enter the following code:
*#197328640#
Select "UMTS". After the code is entered, the phone will automatically open the ServiceMode menu. Here, select "UMTS".
- Click the option in the menu on the screen. If you made a mistake, you can press the Menu button on your phone and select Back.
Open the Debug menu. On the UTMS menu, select "DEBUG SCREEN" (Error correction screen). On the next Debug menu, select "PHONE CONTROL". Finally, choose NETWORK LOCK from the Phone Control menu.
Select "Perso SHA256 Off". Wait about 30 seconds, then press the Menu button and select Back. Click on "NW Lock NV Data INITIALLIZ".
Wait and restart. After selecting "NW Lock NV Data INITIALLIZ", please wait about 1 minute and then reboot the phone. There will be no confirmation message that the process was successful, so check by inserting a new SIM card. If your phone doesn't ask for the unlock code, you're successful.
- If this method doesn't work on your phone, contact your carrier about an unlocking problem or pay an unlocking service fee to get the code.
Method 4 of 4: Unlock Samsung Galaxy S4 manually
Make sure your phone is compatible with this method. This method only works for AT&T Galaxy S4 and T-Mobile in the US. Besides, the device must be a pure phone; Android with custom ROMs won't be compatible.
- This method is almost not applicable to CDMA phones like Sprint and Verizon in the US.
Open the calling app. You need to enter the code in the dialer to open the Service menu. Once the dialer opens, enter the following code:
*#27663368378#
Select "UMTS". After you enter the code, the phone automatically opens the ServiceMode menu. Here, select "UMTS".
- Click on the menu option on the screen. If you made a mistake, you can press the Menu button on your phone and then select Back.
- Service Mode is very powerful diagnostics menu of phone. You should only change the specific settings shown in this guide. Any other changes may cause the phone to become inactive.
Open the Debug menu. On the UTMS menu, select "DEBUG SCREEN". Next on the Debug screen, select "PHONE CONTROL". Finally, click "NETWORK LOCK" on the Phone Control menu. advertisement
Select "Perso SHA256 Off". After you have made your selection, the screen will display this content:
SHA256_ENABLED_FLAGSHA256_OFF => SHA256_ON
Click on the first line. After you click on the option "SHA256_ENABLED_FLAG", the phone will display:
MENU NOT EXISTPRESS BACK KEY
- To continue, press the Menu button on your phone and select Back.
Make sure the settings are appropriately changed. When you back up, the message in step 4 will be displayed as:
SHA256_ENABLED_FLAGSHA256_OFF => Not Change
Go back to the UMTS menu. Press the Menu button and select Back four times until you are back to the UMTS main menu. Then, select "COMMON" then click "NV REBUILD". The screen will display the following message:
Golden-Backup existYou can Restore Cal / NV
Restore backup. Select "Restore Back-up" on the NV REBUILD menu. Phone will reboot automatically. Now that your phone is unlocked, you can insert your new carrier's SIM card. If the machine does not ask for the unlock code, the process is successful. Check if you can connect to the mobile network.
- If this method doesn't work on your phone, contact your carrier about an unlocking problem or pay an unlocking service fee to get the code.
