Sabre 500 Start-up issue

[Mits]

Hi Fellas
I'm trying to put back on service a Sabre 500 with an Acramatic 850SX
controller, the controller turns on Ok but stays on System Start-Up screen
showing that every system passed the boot up test ok except for
ANALOG CHANNEL , showing that this one failed the test, this machine
was moved and I have been told that was running Ok before the move, so
my guess is that maybe a cable is loose or is something simple, I have the
programming manual, the parts manual, the operating manual, the parts
manual, and the control reference manual but not electric diagrams or
electronics for this machine, so I have no idea where to look at, ( my guess
is that it reffers to an analog card interface, could somebody confirm this? )
could somebody point me in the right direction on where to look at for this board, or have any information on this.

Saludos
Jesus Yanes