Replaced power board D1001975 inside aLIGO HAM ISI Interface Chassis S1201747.
Replaced two AD8672ARZ Opamps inside aLIGO HAM ISI Interface Chassis S1201746. 

Units were cabled with external cables (3 Pin power cables) that feed power to CPS units. Before powering up the CPS units, I used a voltmeter to see the output at the end of the cable and discovered a 7 volt drop on the minus leg. The cables had the third pin tied to shield. This drew excessive current from the power board. The connection to the shield was disconnected from pin three. When the ISI Interface units were powered back on, the power board had one of the rails dead and AD8672ARZ outputs were railing on one of the GS-13 boards.