> The question then is, how does the signal get from the CPU card to the
> drives on top? Is there a cable plugged into the CPU card's DSSI port? and
> if so where does it go?
> --Chuck

Well, simple : there is no cable.
I dismantled all my VAX for that : the only cables are the
TQK70-TK70 cable for the tape, and the memory cable.

Apparently, the DSSI signal goes to the disks by the backpane cards.

Check the connectors on the left side of the card slots.
I don't know what it is.
The upper one looks like a centronics with a red plastic cap.
The lower is smaller and have a teminator with a green LED.
Maybe it is a DSSI teminator. If you don't have it, maybe
it is the source of your problems.

Pierre-Michel