Bently Neveda Power Supply and Ribbon Damage

If the old cable connection is a standard ribbon connector (and not a discrete wire termination socket where the ribbon is separated into individual wires and terminated) then unless there is a section that is cut out and twisted or something as is done with HD cables it would be straight through. just look at the old cable and see how the ends were terminated and ohm it out if there is any question and go from there. you can buy the bits at Digikey or Mouser or Allied or any of the other electronics supply places.

If you replace the ribbon cable it will fail again if the environment is too hot. It is also possible the 7200 monitor electronics will fail due to overheating.

Since this must be quite an old system, it is possible someone has removed heat insulation (originally fitted to protect the monitor) and not replaced it - thinking it will save work. If so, they have caused a lot of tripping and trouble.