16
Lenovo System x3850 X6 and x3950 X6 Quick Start Guide
Figure 12 Install the Primary I/O Book
If an I/O Book is removed without first pressing the attention button (Figure 13) on the I/O
Book to shut off power to all adapters in that book, I/O Books can cause the system to
experience instability.
Figure 13 Attention button
Use care when installing PCIe cards so that the metal PCIe card retention latch is fully
seated. Failure to properly align and seat the retention PCIe card retention latch can lead
to either PCIe cards becoming loose (causing system stability issues) or the PCIe
retention latch to break when the I/O Book is installed.
With back-level firmware, the middle slot on FH/FL I/O Books can become disabled. This
is connected in UEFI 1.0 (BuildID A8E112A).
Fan-pack 9
Fan-pack 10
NMI
button
Serial port
USB 2.0
connectors
Systems
management
ethernet port
3V battery
error LED
I/O board
error LED
Locate LED
System
power LED
System
error LED
VGA video
connector
Power LED
Attention LED
Attention button
