X-pro2 audio very staticky

I bought the X-Pro2 last summer for stills, not for video, but occasionally I try out the video. Problem is, the two or three times I've made videos on the X-Pro2 the captured sound is so full of loud static as to mask any other sounds, even when I turn the microphone level adjustment down to its lowest setting of 1.

I'm assuming I am doing something wrong but perhaps audio just doesn't work on this model or (I hate to think) it needs a service. If it's the latter I'll just live with it...

X-pro2 audio very staticky