If you are in a 3G area, try setting your phone to CDMA and see if that helps.
But you do know that the newer phones (later S4's and newer) have Spark tri-band, and in order to allow for all 3 newer wireless bands, only have 1 radio antenna, and cannot use internet at the same time as a call, for the near future (until VoLTE - Voice over LTE is implemented is implemented on towers).
I see that most of these posts are from a year ago. Is there a fix yet? Our Galaxy s5's just started doing this in our home 03840. Doesn't seem to be a problem when my husband just went out to the barn a few 100 yds away. We've been sprint customers for over 15 years, and suddenly we can't get calls while at home. I tried the airplane mode fix, but it only worked for one call. Is there something else?
I tried the sprint app and was able to make one call to the phone changed and reset settings, but any further calls went directly to voicemail. There is no problem with the network according to the app, it passes anywhere in my house. My service "bar" is at one, but if I'm outside or at the window on the north side of the house, the calls go through no problem. If I remove the phone from the windowsill , I seem to have no service, calls go directly to voicemail. If on the windows at the south side, no service but still have one bar indicated.
I just renewed my contract, we've been with sprint forever and NEVER had no service in the house. Yeah, the GPS puts us across the bay at times, but that isn't an issue for me. Everything is turned on, 3g, 4g, wireless (full connection there). The LTE wheel comes and goes. Why am I suddenly in a dead zone and how long will I remain there if they are upgrading the system?
This is now happening with my husbands phone as well. We both have the Galaxy s5. The other phones on the account are not currently residing here.
My son and daughter in law are also experiencing this problem occasionally as well. They live down the road from me.