Network issues + mmi code error on Samsung S7

[Android Central Question]

Hi team,

I bought a S7 in Vietnam that was working fine on the local network. I brought it back to France with me and ever since I struggle a lot to get the phone to work properly. I bought a French sim card and the network name shows up but I'm unable to make phone calls and internet works only very rarely. Extremely frustrating as you can imagine. I often have the message "not registered on Network" or "MMI code invalid" displayed on screen.

I've read online that the issue could be from the radio that is on but when I enter the service mode I can not find anywhere on how to switch it off. The phone is a SM-G930S LTE, original netzork is SK Korea. I've checked the IMEI and it appears to be clean, at first I thought it could be blacklisted but it isn't.

Any idea to get this fixed please?

 

[mustang7757]

Hi, welcome to Android Forums

I'd like to recommend creating a account so me or other members can assist you, as guest have limitations in replying here and if we need further Information to communicate with you.

I'll provide a link to register, please come back to your post so we can further assist you . Thank you

https://forums.androidcentral.com/showthread.php?t=409154

 

[mustang7757]

Should talk to that carrier for the right APN configuration

 

[anon(10614692)]

It's not 100% compatible with all 4G bands but you shouldn't have the problems you are having https://www.frequencycheck.com/comp...sm-g930s-galaxy-s7-td-lte-samsung-hero/france

Having said that the error messages you are getting suggest a weak signal. I think this is something you need to discuss with your network provider