Hello !
My problem is that my sim800L fails to register to a network. Tested 2 sims no luck. I am running it with an 3.7 1200 mAh Li-po battery and the signal strength is excellent (23).
But at the beginning when I start the module up I write AT+CREG? and it returns +CREG:0,2 and after a few seconnds it returns +CREG: 0,3. Aside from this I wanted to check my IMEI and found out that it doesn't look the same as the one written on the module itself.
As far as I know changing the IMEI is illegal. I want to add that with the Vodafone sim I had no problems on other gsm modules such as A6.
2g network shutdown USA
Summary of 2G Network Shutdown Announcements
Carrier 2G Network Shutdown Date
AT&T 2G Network December 31, 2016
Verizon 1xRTT Network Shutting down CDMA 1X network: December 31, 2019
T-Mobile Committed until December 2020
Sprint Committed until 2021
As you can see, most of the 2G networks in the USA have been shut down. You still may be able to find some service if you try making sure you're within one of the networks that are still up and running.
SIM 800l ONLY supports 2G cards, so if you tried using any card that wasn't 2G it won't work, and if you are using 2G and outside of connection range it won't work either.
We still have 2G in Romania. At least I have read that even in 2019 Vodafone Romania still has 2g