"Richard" wrote in message
oups.com...
Thanks for the replies. I agree with the controller/switch assessments
-- but what are the odds that 4 controllers (3 in the original unit and
1 in the new one ) would all be bad? Or that the switches would also
be bad in two units? I'm beginning to think, though, that both units
and all the controllers might come from the same subcontractor or
assembly plant -- i.e., there is a batch of these things out there
coming from the same source.

It happens. A good tech can figure it out.
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N