No cellular service after switching SIM from GSM to CDMA and then back again


What phone do you have? Moto G4 Plus

What plan are you on? My Choice + 1 GB

Does your plan include data, or just talk & text? Yes, data

Issue Description##

After switching my SIM card from GSM to CDMA and then back to GSM I have lost cellular service. If I call someone while on wifi or after being on wifi the cellular signal appears again but as soon as I shut wifi off or try to call using cellular the call will not go through and the signal drops off. Sometime after shutting wifi off the LTE, 3G, and H indicators cycle through before going back to an empty triangle. I have tried to reset the network settings multiple times, and redid the activation multiple times.


Check this out (there are some time limits) Can I Switch Back to the GSM Network After Trying a CDMA SIM Card? – Republic Help


Thank you very much for the response. It has been only 17 days since I opened the request for the CDMA card and it took a few days to arrive so it must be less than 20 days. I have a help ticket open for a day now and still no resolution, this is getting frustrating.


Hi @douglass.5eplw5,

The empty triangle suggests no cellular coverage on GSM. Did you have GSM coverage before the requested switch to CDMA? May we know the reason for the switch back from CDMA to GSM? Was CDMA coverage worse that what you previously had on GSM? Frankly, you’ve already tried what the Community might suggest as far as GSM coverage is concerned.

A couple of final thoughts. Might we know the zip code where you’re having this experience? And, since you mention an open ticket, may we know the ticket number and how long since the most recent response?


Yes CDMA was worse, I was having good service in my area 02359 and most of new England with GSM except some northern parts of maine so I tried CDMA and it was worse locally 02359.

Ticket# 1463745



When you went through the activation process to get back on GSM…did that complete satisfactorily…or were you never fully activated back on GSM since being on CDMA?

If you don’t mind taking a drive 60 miles north… I can give you one of my spare GSM sim cards
and you can try if you can get it activated. DM me if you want to explore that option. If you already have a response on your ticket then that would be the surest method to get this resolved…but just trying some out of box thinking…in case you are stuck without coverage.


Hi @douglass.5eplw5,

When I examine coverage in and around Pembroke, I do see areas of “fair” signal strength. Indoors, “fair” sometimes means non-existent. A drive to an area closer to the center of Pembroke and repeating the Network settings reset there might help.

Meanwhile, I’ll inquire with staff regarding your open ticket.


I switched back to the CDMA SIM card and now I am in a continuous cycle of updating MDN settings and rebooting when I try to make a call, the phone will call over wifi,but the cellular signal seems to cycle between different modes. Eventually I am able to make a cell call, and send a cellular data text, but the cellular signal indicator keeps changing modes. Very strange and the calls and text seem to take a long time and are unpredictable, this is why I decided to switch back to GSM. Not sure what to do now, tech support might send me a new GSM SIM or they think my antenna might be bad.


Hi @douglass.5eplw5,

I’m truly sorry for the experience. Generally, attempting to troubleshoot the same issue here in the Community (where we can often help) and via support ticket simultaneously is more hindrance than help. That said, has support suggested this: How to Reset Cellular Settings on Motorola, Nexus, and Google Phones with CDMA SIM Card – Republic Help.

If that doesn’t help, it would be best to continue working with staff. Trying a new GSM SIM is probably the next step, however, there may indeed be an issue with the phone itself.


Thanks I understand, I was trying to get all the help I could as technical support is not very responsive and I still dont have cellular service.


Hi @douglass.5eplw5,

I do appreciate the dilemma and I don’t mind trying to help. That said, if we’re at the point of looking at the SIM and/or phone hardware, realistically that’s going to require some time into next week. By any chance, did you upgrade to the G4 Plus from an earlier Republic phone? If so, do you still have that phone? Admittedly, I’m grasping at straws here.


Roland, SO good to find you here!
Doug, I found him spot on on understanding my question! …
Could it be a time issue? I am getting a similar issue when I go CDMA -GSM route. I just received a new GSM SIM card to use in my Moto G5+ to swap out mt CDMA SIM card. (Due to upcoming International travel.) I read somewhere it takes up to an hour to complete the process and while it only took a few minutes for my phone to update, I wonder if the hour time-frame is for the cellular system’s updating with the New SIM card/one IMEI info? (I tend to have a hard time just waiting! :wink: ) Roland, what do u think?


I moved my SIM GSM card to another phone and it worked fine assuming it’s my phone at this point I bought a new Moto G6 and I might send the old one to Motorola to see if it can be repaired.



Hi @jonathans.wd591y,

Activating a Republic SIM can indeed take up to an hour, though it’s usually much faster. Have you received an email from Republic indicating your activation request has completed?


Yes, I received the email of successful completion of activation. However on the GSM service I only had emergency calls available. So I switched back to the CDMA card for now. (I figure I’ll switch to the GSM one when I’m in Canada.)

Jonathan (via mobile)


Just note a SIM becomes invalid if deactivated for more than 20 days


It sounds like there is no GSM coverage at your current location (probably why your phone was originally provisioned for CDMA). To prevent the potential issue mentioned under the heading " Republic 3.0 Phones" here; International Travel with a Republic Phone, I strongly suggest placing your phone in Airplane mode then reenabling WiFi just before entering Canada. Leave your phone in Airplane mode until you have the opportunity to swap the GSM SIM in for the CDMA SIM.


Thanks! … I’ll just switch every week - a new weekend routine! :slight_smile:

Jonathan (via mobile)


Thanks for the counsel on airplane mode while in Canada; will do that.

As for GSM coverage here, that should not be the issue: I used to be on AT&T two years ago and had excellent coverage. I doubt it has changed much since then. (and looking at T-Mobile’s coverage map of the area shows very few holes; none near me.) SO, I’m guessing/hoping it’s just a matter that I didn’t wait long enough for the towers/system to update. Besides, I don’t really expect to stay on the GSM system while in the states.

Thanks again.