[Elecraft] KAT1 - stumped

[Mike Zak]

Hints appreciated:

I have a complete K1-4 that works GREAT and I have been having a load of =
fun with it.  It has RF Board Rev E and Filter Board Rev B.  K1 MPU rev =
109.

I decided to go ahead and construct the KAT1, which is on PCB Rev. C.  =
As many of you know, there aren't a lot of parts on it and it goes =
together quite easily.

I went ahead and mounted it on the filter board, disconnected R36, and =
have been unable to power it up.  When I scroll to the ATU portion of =
the menu, and try to EDIT, I get the dreaded three dashes  "- - -".

Just went through the troubleshooting suggestions in the manual, which =
are kinda sparse.  Reseated the KAT1 MPU, went around the socket for U1 =
and reheated all the pins on the bottom of the board.  Verified that K1 =
firmware release is 109, looked for solder bridges.  I have enough =
experience with these designs so far (a Norcal 40a and the K1) to know =
that they usually work when you bring them up unless you've done =
something pretty dumb - any suggestions as to what I could have done (or =
not done) to fail to get the K1 controller to register the presence of =
the KAT1?

Mike - W1MU