Pixhawk 2.4.8 doesnt heartbeat

My pixhawk was working fine.Standing still it doesnt work. When i start my Pixhawk, there is no heartbeat and there is some ugly voices .When i connect to pc via usb , than i saw that messages.I had an old version of firmware than i updated it but nothing change. Please help me.

For assistance with ArduPilot, best to visit discuss.ardupilot.org