The new telecom card doesn't have 3g signal, but it has 2g signal, so you can't make phone calls and send short messages, but you can surf the Internet.

1 First of all, the mobile phone supports telecom cards, but the signal of the mobile phone card itself is different. Change the mobile phone card to another mobile phone to see if there is the same symptom. Note that you should use a mobile phone that supports 3g standards. If the problem still exists after replacing the mobile phone with another mobile phone, it should be the problem of the mobile phone, or at least the setting of the network operator.