I can get a short message when I make a domestic call in the United States, but what is the reason why I can't dial the number?

In the United States, the reason why the cell phone signal is weak is that you can receive short messages when you make domestic calls, but you can't dial the number. Weak or no signal from the mobile phone card will make it impossible to make and receive calls. You can try to re-register the network by switching flight modes. Ensure that the phone bill balance of the mobile phone card is sufficient, and restart the mobile phone after successful recharge to prevent arrears and downtime.