Ed A wrote:

 
Bernie,

A faulty switch could certainly be the problem - just a chip of metal in the
casing that could short a couple of pins in the switch just for a tiny
fraction of second would do it.  Also some of the "Make-before-Break" are
"spring" loaded such that the "Make and Break" happen in 10s of
milliseconds, so it might not register on anything less than an oscilloscope
type instrument.  The fact that you are apparently not frying any more chips
with your single switch would to me strongly indicate:

1.  Wiring error (which I would consider highly unlikely the number of times
you have been over the wiring)
2.  A defective switch (which might account why the EC2 survived for at
least some amount of time before blowing)
3.  A "Make - before-Break" switch(es) in the batch of three

Ed A

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Ed,

Tracy pretty much ruled out item 3 since they would not transfer 12 volts from one side of the switch to the other, only to the open position on the same side of the switch.

I ruled out #1  :>)

Bernie, sucessful cold start yesterday