About a year ago my 87 camper went DEAD.  No spark, no nothing-turned out
to be a dead ECU.  A scenario followed that will be familiar to many
listmembers-nationwide parts search, finally got a used one and after weeks
got it running.  I considered it an unserviceable black box and just put
the old one on a shelf in my garage.  This weekend I was piddling around
and, despite my  minimal knowledge of electronics, decided to take it apart
and see if there was anything decipherable that could be seen.  Sure
enough, between two contacts sat a tiny washer, the same kind of washer
that was used to hold the green board in place.  I removed said washer, put
this formerly dead unit back in the van and it started right up. Continued
to restart on multiple tries.  Didn't quite have the courage to leave it in
and drive anywhere I couldn't walk back from, but I may have a spare ECU. 
Moral is- don't be bashful-look inside.

Bill
87 camper and
another 87 camper