Pixhawk can't connect to the computer via USB or RFD

Hi. I have using Pixhawk 2.1 for almost 6 months and It was working properly. I have tried to connect storm32 gimbal controller card with telemetry 2 port today. It was worked properly first and then I have calıbrate the parameter “MNT_MODE;_IN” and I have selected the AUTO and then I have tried to reboot Pixhawk 2.1 and then It didn’t connect to computer when I tried. Also I have tried to connect via RFD and Qground or MissionPlanner(I have tried both) can’t recognize the pixhawk. Also GNSS LEDS don’t lighting now. I have tried to connect with debug port via USB cable and I have seen “USB Portal(COM3)” in the device management.

What I must to do? I think If I can reset to Pixhawk, It can be fixed but I couldn’t find how I reset the device. How can I reset Pixhawk without connecting to computer? or Is there any way to fix this problem using via debug port?