Help Galaxy S7 loses cell service

[Lord Volvo]

My Galaxy S7 sometimes loses connectivity with Verizon cell service - I can't send or receive calls. I have to restart the phone every day which fixes the problem but only for a few hours to a day. The screen shows LTE+ when it's talking to the towers and I see signal-strength bars. Sometimes these indicators are there but still my calls don't go through, then the bars disappear.

The network mode is on Global but I've tried the other settings as well (LTE/CDMA and LTE/GSM/UMTS), but that didn't change anything. The screen shows LTE+ when it's talking to the towers.

I've tried resetting the phone but that didn't fix anything - just caused me to lose my WiFi settings. I haven't tried a factory-reset yet.

I'm working with Credo Mobile techs but they think I need a new phone, which is a last resort since I don't want to spend money unnecessarily and go thru the trouble of reorganizing apps, settings, etc.

Help!

 

[mikedt]

Could be a faulty SIM card, that needs replacing?

 

[AugieTN]

Your phone came out in 2016 so it's almost 7 years old. Try a new SIM and if the doesn't work try a factory reset.

 

[svim]

Well your S7 is a seven year old phone, quite dated for a smartphone.
https://www.gsmarena.com/samsung_galaxy_s7-7821.php
It doesn't even include support for 5G but that's not likely an issue in your case, 4G/LTE is still prevalent here in the U.S. Try re-seating the SIM card. Not likely to be the source of the problem but worth trying. Or try getting a new SIM card from Credo to see if that makes a difference.

Do you recall if your phone was previously using Sprint's cellular network? Credo is just a MVNO carrier that contracted to use Sprint's network. A couple of years ago T-Mobile bought up Sprint and has since that time been decommissioning Sprint's cellular service. Apparently Credo is now contracted with Verizon instead. Go into the Settings menu and check the selected APN entry to see if there are still references to Sprint. It might be a matter where you do need a new SIM card from Credo.

 

[Hadron]

I think this probably is either new SIM or new phone. A failing SIM can cause loss of network connection (you might get a symbol to indicate no SIM present, but I don't guarantee it), and a restart may temporarily fix that. If this is the cause it will become more frequent and at some point just stop working, but a replacement SIM will fix that. But it might be the phone instead, in which case it is probably not economical to fix (since "fix" will generally mean "replace the motherboard", assuming someone can still get hold of one). So personally I'd try asking for a replacement SIM, and if that doesn't fix it accept that you need a new phone.