I have 2 pro s2b part number is 30010242-02 rev a. One of them work well. The other one connect with Arduino wireless shield, the PWR LED always blink. Turn red for 1second then turn off for few seconds then turn red again and then off. when I use XCTU 184.108.40.206 version to test the modem. It shows unable to communicate with modem. It was working well when I first use it. I uploaded an API firmware and then it comes with this problem.
Can you guys help me?