Galaxy S8+ connection problems

zvolts

    I’ve been a T-Mobile customer for a couple years, with three lines. With a T-Mobile tower almost in my backyard, all devices generally have max bars. Two lines are iPhones and one is the Galaxy S8 plus. The S8+ (Factory unlocked)  was my daily driver for about five months and I never had significant connection problems with it.  Couple weeks ago I bought a new iPhone and made it my daily driver, swapping the Sim card from the galaxy to the new iPhone and then then iPhone Sim to S8+. Since that time the galaxy will not connect to T-Mobile. At home, it always latches onto an AT&T tower in roaming mode. I’ve reset network settings, removed Sim/reinserted, rebooted the S8+ numerous times, no help. When I try to force th S8+ to a T-Mobile tower, the connection attempt just times out.  I’ve called T-Mobile support and they were of no help, saying I’m too far from a tower.  At home the tower is 3/10 of a mile from my house with line of sight. My iPhones get Max bars to T-Mobile, as did my Galaxy before this issue. I've even moved the original daily driver Sim (now in iPhone) back to the S8+, it still won’t connect to T-Mobile tower.

     

    Anybody have any ideas?

     

    Thanks.

      All replies

      • snn555

        Re: Galaxy S8+ connection problems

        I think in this situation I might attempt to ask T-Mobile for a new SIM card. It's possible though unlikely and very rare that some sort of change happened and if everything is working fine except for the Sim when it is in that phone there may well be a problem with that SIM card. Perhaps you can try another sim from another device if you have multiple lines and see if perhaps that person's SIM card works in your S8 Plus.

        1 of 1 people found this helpful
        • tmo_marissa

          Re: Galaxy S8+ connection problems

          Hey there! Just wanted to check in and see if this SIM update idea was helpful -- I know there hasn't been a ton of time since your original post, but have you had a chance to try this out?
          I also wanted to check and see if it's possible that perhaps the APNs for your factory unlocked S8+ got reset when you placed the new SIM in the device. Have you had a chance to double check them against the ones linked in our Bring your own device setup guide to make sure that something didn't get funny with the SIM change?

            • zvolts

              Re: Galaxy S8+ connection problems

              Thanks for the replies.

               

              As I wrote in my original post, I have already tried a different Sim, the one from my iPhone. No go.

               

              The only APN on the phone is set as in this doc:

              Network, APN: Samsung Galaxy S 5

                • tmo_marissa

                  Re: Galaxy S8+ connection problems

                  Yikes, that's super strange. TBH, I think that snn555 was suggesting an entirely fresh SIM (which is what I was thinking as well), but if you're placing the original SIM back in the device and it's still not working, then I don't know that a new SIM is going to resolve the issue -- sometimes it's worth a shot.

                  If your APNs look the same as the generic settings I linked to, or these: Network, APN, and VoLTE: Samsung Galaxy S8+, and you're still having trouble, then I'm at a loss. I can't imagine why the device would work on the network just fine until the SIM was changed without the issue being either 1. the SIM, 2. the APNs, or 3. a terribly timed network issue. What's the ZIP where you're currently located? 

                  1 of 1 people found this helpful
                  • tmo_mike_c

                    Re: Galaxy S8+ connection problems

                    Hi there!

                     

                    Just checking to see if you've had the chance to reference Marissa's post and give the APN settings a shot. Please let us know if you still need some help. Thanks!

                • tmo_chris

                  Re: Galaxy S8+ connection problems

                  Just checking in here to see how things are going. Please let us know if you still need any help.

                  • zvolts

                    Re: Galaxy S8+ connection problems

                    APN is fine. I'm selling the thing and disconnecting it's 3rd line.  Samsung blames T-Mobile, T-Mobile blames Samsung.  The odd thing is, this is the second S8 plus I’ve had with essentially the same problem. This one replaced the defective first one.

                      • tmo_chris

                        Re: Galaxy S8+ connection problems

                        Oh man! I am very sorry you are still having this issue! If you haven't already sold the phone. it might be worth doing a factory reset on the device. It was working when you first started using it so something must have changed. Also, I don't know if we clarified this or not but are you able to connect to T-Mobile in other areas with the S8? If so, what is your home ZIP code and what is a ZIP code of an area that you are able to connect to T-Mobile.

                      • tmo_chris

                        Re: Galaxy S8+ connection problems

                        Thanks for the info. You should be picking up LTE 700 as it is a bit stronger than the 2100 that is also available in your area. The area is not listed as roaming so there is no reason you should be connecting to a roaming partner. The tower that serves your area is actually about 2.5 miles north up in Greenbush. When you travel up State ST toward Greenbush, are you able to pick up T-Mobile on your S8?

                          • zvolts

                            Re: Galaxy S8+ connection problems

                            I live 12 miles from work. There are different T-Mobile towers within 1/4 mile of both my home and work, with no T-Mo coverage in between. I normally roam on AT&T between the two locations for about 4 miles or so. 

                             

                            On the way into work today, I brought both my T-Mobile S8+ (problem phone) and iPhone X with T-Mobile SIM, which has had no connection problems.  I power cycled the S8+ at home before I left for work. It latched onto the AT&T roaming like it has been. iPhone is on T-Mo as it should be. I drove right up to the T-Mo tower near my house and park. S8+ still on AT&T. I tried to force (Settings/Connections/Mobile networks/Network Operators/Search now – then Select T-Mobile) the S8+ to connect T-Mobile tower. It just spins saying “Trying to register to T-Mobile”. It’s still connected to AT&T. I then start driving away as the S8+ is still trying to connect to T-Mobile. It finally times out when I’m about 3 miles away from the home T-Mo tower, but it’s still connected to AT&T. iPhone still has T-Mo.

                             

                            Half way to work my iPhone loses T-Mobile and picks up an AT&T roaming like it normally does. When I’m 3-4 miles from work, my iPhone picks up the T-Mo tower that is close to work (zip = 48750). I park and try to force the S8+ to T-MO – it’s still on AT&T. It just spins. I start driving. When I’m about ½ mile from the work T-Mo tower, the S8 picks up T-Mobile! I get to work (1/4 mile from T-mo tower) and phone is still connected to T-Mo and seems to be working fine. I reboot the S8+ and it connects back to T-Mo just like it should. I do a speed test and get 82 Mbps – definitely not roaming!

                             

                            Interestingly, about a week ago, I brought the S8+ into work and tried to force it to T-Mo. It didn’t connect, staying on AT&T roaming. But, hey, this is progress!

                             

                            So why can’t I connect to the 48738 T-Mo tower with the S8+?