EC21 SIM card detection problem

IoT Modules LTE Standard Module
1

Our product is using EC21. The EC21 module cannot detect SIM card. We have try many SIM and got the same results.

We check the electronic circuit connection between SIM card socket and EC21. The connection is right.

Does any expert know the cause of the problem ?

Thanks.

2

Hi @wktam
I think if all SIM cards are not recognized, it is recommended to check the SIM card seat connection first, and you can try to replace the SIM card seat.