if you're using the mia material you'll need to plug it into cutout opacity
take a look at this i recorded it sometime ago for another user who asked a similar question.
https://www.youtube.com/watch?v=KFsLE76oZgk
From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"