We have had a couple of EX1s go into the shop with this issue its either the audio board itself or the ribbon. Usually its from stress on the handle assembly. The ribbon that attaches the audio … thing.. into the camera itself is in the perfect spot to get pinched and broken. We have had to send every one with this issue to Sony, our Engineering department wouldn’t touch it.
Hate to be the barer of bad news, but sounds like the same issue we had. Good luck.
-Jacob
News Photographer / SNG