Sorry to hear about the signal issues. If it is stuck on ATT then yes that is a signal issue. Go ahead and try these steps.
Perform manual network selection
To manually select the wireless network the device connects to, follow these steps:
- From the Home screen, select the Menu icon.
- Scroll to and select Settings.
- Scroll to and select Network.
- Select Network selection.
- Scroll to and select Select network.
- Your phone searches for available networks.
- Scroll to the desired network.
- Select OK.
- Note: The device detects and registers on wireless networks inside T-Mobile’s calling area, but roaming networks are usually restricted to T-Mobile SIM cards. You can manually select a network only in areas where T-Mobile does not own GSM spectrum.
Let us know if this resolves the issue
i just bought my phone the other day and have had the same problem i found out today whats going on when it stays in emergancy mode it is a signal prob yes but also its because the network when set to auto search searchs for any network that has signal at the momment so if u have no signal from tmobile at the momment and is another service signal at the momment it will try to connect to that such as AT&T i found out i walked down the road turned to manual find service and then i turned off my phone and back on and it worked fine so just most likely turn off the auto search under networks and then turn the phone off then on and it will only use tmobile network and not try to connect to AT&T network if there isnt any signal to tmobile when u turn the phone back on hope this helps also i tried to connect to the tmobile network and it started to register but then it didnt go thru and tmobile vanished from the list kept trying but wouldent see it pop up silly cause it was already registered to tmobile not fun that it trys to auto connect to AT&T when no signal from tmobile.
well mine decided to goto emergancy mode again what u need to do if it does goto an area that has signal i have to walk down the road and then turn it on cause it connects to tmobile and doesnt try connecting to AT&T which it does if turned on with no signal a real pain really to either have to be in a good signal zone or go down road or where ever there is good enough signal to kickstart it
if still no luck try putting on to manual network then search then goto a area with good signal and turn it off then back on so 1st signal it picks up on is tmobiles and then it should auto connect every time to tmobile and if it ever kicks off blackscreen for min then goes emergancy mode and wont connect just turn it off then back on hopeing it helps never actually know what the problem is fully but is always many things to try