Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 769)

Section 15B
Replacement Procedures
15B-13
In the case of hardware failure,you may be required to replace the
motherboard. When you remove the motherboard from the enclosure, you
also must remove the software option chip. This chip turns on all the
optional features that you purchased with the control. To replace the
motherboard:
1. Turn OFF all power to the control.
ATTENTION: To guard against electrical shock hazards, never
make connections or disconnections at the ac distribution
network unless the main ac disconnect switch is open and
locked.
2. Remove all connections to the motherboard, including:
battery
fast I/O
I/O ring
E-stop wiring
video
RS-232/RS-422 communications
3. Remove all modules connected to the motherboard, including:
CPU board (see the previous procedure)
analog or digital servo modules
optional communication modules
remote I/O port
15B.4
Replacing the Motherboard
on the 9/260 and 9/290