Modem 30 minute lockup

[Burt]

This is driving me totally nuts. There are inconsistent pieces of information in documents and code. I am getting a modem reset loop problem. The documentation says the timer does not run when the modem has no power. That tells me I have to leave power on in order to get out of this ridiculous mess that cuts me off from any and all LTE-M and NB-IoT networks. The message from some asset tracker code tells me I can get out by doing a power reset, but that does not work.

How in blazes do I get out of this fricking mess????? This is at least one day down the drain.

How about 5 minutes rather than 30 minutes. How about something that simply restores the modem?

Did I put a bug into the code? I can't imagine how, although I do put in printfs.

Thanks.

Burt S.

[Achim Kraus]

Sometimes long network searches may be caused by multi-imsi-SIM-cards with auto-switching. You may check that by reading the IMSI (AT+CIMI) frequently, e.g. every minute. If it changes, the modem usually restarts the network search. It's only one cause, but sometimes a nasty one. Even if it doesn't apply in your case, it's good to know it.