Continuous Buzz in Start Up

Once the pixhawk2 cube gets started, its buzzer keeps beeping at a high frecuency. The cube Leds keep being red and blipping at a similar este to the buzzer. When connected by USB to pc It is not recognized by mission planner. I have just looked inside its componentes and no aparent damage or corrosion.

I alwo tried uploading new firmware through USB, not recognized port either