Pixhack 2.4.8 booting problem

I have a problem when connecting my pixhack 1 (2.4.8) to PC through usb cable as it is not recognized by PC at all . I have checked ports in Windows device manger where there was no errors and no px port , I have solid green (PWR) solid Orange (P/E) flashing Blue (ACT)
before it was working properly when I fly my quad copter but when I tried AP with fixed wing plane it got this problem . I have changed USB cable and reinstall Mission Planner but not thing change I have used safety switch and reset autopilot by little pin inserted on the hole beside usb port but also noting change``