11/780 crash

[utzoo!decvax!harpo!ihnss!ihps3!stolaf!minn-ua!chris]

We just finished with a severe case of the INT-STK NOT VALID's.  In
our case it turned out to be a bad System Industries MBA backplane.
The problem developed after 6 months of use and was supposedly due
to a bad solder joint on a power pin.
The CE had to swap the entire CPU to isolate the problem.
Prehaps your problem is similar?
Good luck.

Chris Boylan
University of Minnesota Computer Center
decvax!pur-ee!minn-ua!chris