Remove The I/O Board - Lenovo 82RB Hardware Maintenance Manual

Step 1. Detach the CMOS battery cable connector and then remove the CMOS battery.
Figure 21. Remove the CMOS battery
Go to https://support.lenovo.com/partslookup
part:
CMOS battery

Remove the I/O board

Make sure the following FRUs (or CRUs) have been removed.
"Remove the lower case" on page 30
"Remove the solid-state drive (SSD) plate (L)" on page 31
"Remove the solid-state drive (SSD) plate (R)" on page 32
"Remove the thermal module" on page 39
Step 1. Disconnect the I/O board cable from the I/O board and then remove the I/O board.
Figure 22. Remove the I/O board
to look up the Lenovo part number of the following replacement
.
Chapter 4 Removing a FRU or CRU
41