How do you know your FI has "packed it up"? If you suspect it has, I suggest hunting through Kjell Nelin's D-jet Guide on the 914 Fan Page.
http://www.914fan.net
It's in the "Tech Refs" section. It does have one typo, though. It says to check the MPS resistance between pins 8 and 10, and between 7 and 10. The second 10 should be a 15, so you are checking between pins 8 and 10, and between pins 7 and 15.
--DD