Rockwell Automation 6189V-xxxx Non-display Industrial Computers User Manual - Manual (Page 47)

Rockwell Automation Publication 6177R-UM002D-EN-P - October 2014 47
Component Replacement Chapter 4
6. For 1450R computers, disconnect the 4-pin power connector from the
PCI expansion board.
7. Disconnect the ATX 24-pin power connector from the motherboard.