Network connect fails when not on wifi

[Gabriel Kroes]

Hi guys

This is my first post here, so please be gentle...

I have recently bought a 2nd hand Samsung Galaxy S10e. After starting to install apps, so of them gave warnings stating that the "Software has been tampered with".

After doing some reading, I noticed that the software said that there was a Custom ROM installed. I took the phone back to Samsung so that they can flash a stock ROM onto the device and they were happy to assist. After installing the stock rom, the phone seemed to be working fine, but when I got home, I noticed that I kept getting "Failed to register on network" or "Cannot connect" error messages.

If you open the network settings and try to manually connect to a network, the buttons are not greyed out, but they just don't work. See video

I'm also not getting any SMS messages. I took the phone to a local phone technician who thought the phone was simply network locked and they try to unlock it with network unlock codes, but it would again only work for a brief period (few hours) before reverting back to this behaviour.

What I have found though, is when the phone is connected to a wifi network, everything seems to work 100%. SMSes come through and the phone connects to networks and can make calls.

Any ideas of how to go about getting this sorted?

 

[mustang7757]

Hi, welcome to AC!

I have the unlocked version Note 20U when I have a sim installed which is att at the moment , it grayed out and won't let me select, so I don't think anything to worry about , if you have another carrier sim try it and see if everything works to know if it's unlocked.

 

[Gabriel Kroes]

I have tried another carrier sim and it also says "Not registered on Network". The technician that tried to unlock the phone said that each time he entered an Unlock code, it would be unlocked for a few hours before diverting back to being locked. I'm not sure how that's possible.

Also, why would I be able to make and receive calls and smses when I'm connected to wifi? If the phone was blocked, shouldn't those be blocked regardless of whether I'm connected to wifi or not?

 

[mustang7757]

I have tried another carrier sim and it also says "Not registered on Network". The technician that tried to unlock the phone said that each time he entered an Unlock code, it would be unlocked for a few hours before diverting back to being locked. I'm not sure how that's possible.

Also, why would I be able to make and receive calls and smses when I'm connected to wifi? If the phone was blocked, shouldn't those be blocked regardless of whether I'm connected to wifi or not?

Not registered could be few things
1. Using a prepaid card with not the features of high tier plans of that carrier.
2. The imei not registered to that device number on the carrier system.

The tech that's not fully unlocking means he doesn't have the capability to fully unlock it.


Is your device international or US version?

 

[Gabriel Kroes]

I'm from South Africa and I'm not sure how to check if it's the US or international version.

The sim is a contract sim. I've tried sim cards of various other carriers in South Africa and they all give the same result. I'm thinking that it has something to do with the IMEI. I have checked if its blacklisted but it comes up clean.

What's the deal though with it working when I'm connected to wifi? That doesn't make sense to me at all...

 

[Gabriel Kroes]

So nobody here can explain or has seen this error where a phone can connect to the network when on wifi but fails to connect when wifi is not connected?

 

[B. Diddy]

What's the exact model number of the phone? Go to Settings>About Phone to find that info.

Also, which carrier are you using?

 

[Gabriel Kroes]

Model is SM-G970F

Carrier (I'm assuming network provider) is Telkom in South Africa. But as mentioned, I've tried various others such as Cell C, Vodacom and MTN , which means I have covered the 4 biggest network service providers in South Africa. All give the same result.

 

[mustang7757]

So nobody here can explain or has seen this error where a phone can connect to the network when on wifi but fails to connect when wifi is not connected?

Model is SM-G970F

Carrier (I'm assuming network provider) is Telkom in South Africa. But as mentioned, I've tried various others such as Cell C, Vodacom and MTN , which means I have covered the 4 biggest network service providers in South Africa. All give the same result.

This means your mobile data not working, you have the international version , look at your APN or talk to customer support to give correct APN for that carrier.

 

[Gabriel Kroes]

The APN settings are exactly the same as my other phone I'm currently using (Galaxy S8).

The only difference I can find in any of the settings is that the SM-G970F doesn't allow me to select Manual or Automatic Network selection as shown in the video above.

 

[Gabriel Kroes]

These screenshots were taken with the SM-G970F connected to wifi or not (shows the same).

 

[mustang7757]

I think it's best to go in store if possible of that carrier and see what they can do with APN

 

[Gabriel Kroes]

I think it's best to go in store if possible of that carrier and see what they can do with APN

Thanks, definitely worth a try. But it does the same for all the carriers. Do I just choose one?

Any reason why the software doesn't allow me to select Manual or Auto?

PS. Can you guys see the video I posted?

 

[mustang7757]

Worth a try.

Any reason why the software doesn't allow me to select Manual or Auto? It does the same for all the carriers.

PS. Can you guys see the video I posted?

I can see the video, might be something that carriers sim do

 

[Gabriel Kroes]

I can see the video, might be something that carriers sim do

That same sim works in the phone I'm using at the moment, so I highly doubt that it's a SIM or carrier issue. But as I said, will definitely give it a shot, but it might have to wait for tomorrow (11pm in Cape Town at the moment).

Thanks for the advice so far

 

[mustang7757]

That same sim works in the phone I'm using at the moment, so I highly doubt that it's a SIM or carrier issue. But as I said, will definitely give it a shot tomorrow (11pm in Cape Town at the moment).

Thanks for the advice so far

I don't think it's a sim issue, I'm thinking a APN issue that needs to be tweaked.

 

[Rukbat]

TelekomSA seems to do strange things with their APN, but the following should work:

Name: Telekom
APN: Internet,mms
MCC: 655
MNC: 02
MMSC: http://mms.8ya.com:38090/was
MMS Proxy: 41.151.254.162
MMS Port: 8080
APN Type: default,supl,mms
APN Protocol: IPv4
APN Roaming protocol: IPv4

Anything not listed, just leave blank.

 

[methodman89]

You have 0 bars showing in the screenshot. Have you looked at the indicator while experiencing this problem?