There is a life span on the PMI modules, and YES they do go intermittant...(Life Span was around 10 years)..

Change out all PMI's in the Reader box, and any others associated with it in the PMI boards upstairs.

It Don't mean a thing if it aint got that swing.

Cool, Free, Johnny Smith courtesy of NPR..HERE
http://www.npr.org/ramfiles/asc/asc25.smith.asx