Rockwell Automation 6189V-xxxx Non-display Industrial Computers User Manual - Manual (Page 49)

Rockwell Automation Publication 6177R-UM002D-EN-P - October 2014 49
Component Replacement Chapter 4
10. Disconnect the +12V 4-pin power connector from the motherboard.
11. Remove the five screws that secure the PSU to the chassis and chassis
bracket.