I had the same problem with my ML 380. I have sent it off to the Service Bench in MA. to be re-furbished. When I talked to them about the problem they gave me the impression that it was a software problem. I'm also have the unit upgraded with new cap's.
Try calling ML to see if there is a reset. They helped me when my ML 39 drawer did not work and told me how to reset it.
Joe Nies