IBM x3100 M5 Type 5457 Installation And Service Manual page 339

Figure 245. Pushing external input/output connectors into chassis for 5U server model with
hot-swap power supplies
Attention: When inserting the system board external input/output
connectors into their respective holes in the chassis, make sure the EMC
springs are not inserted into the holes. Inserting the EMC springs into the
holes in the chassis could damage the EMC springs.
Figure 246. How to correctly insert EMC springs
5. Align the holes (seven in total) on the system board with the respective
standoffs on the chassis.
EMC spring
Chapter 6. Removing and replacing components
323