HP Engage Go Convertible System Hardware Reference Manual page 33

Turn off the mobility system properly through the operating system, and turn off any external devices.
1.
Disconnect the power cord and all peripheral devices from the I/O connectivity base.
2.
Regardless of the power-on state, voltage is always present on the system board as long
IMPORTANT:
as the system is plugged into an active AC outlet. You must disconnect the power cord and wait
approximately 30 seconds for the power to drain to avoid damage to the internal components of the I/O
connectivity base.
Remove the five screws on the underside of the I/O connectivity base (1) that secure the bottom plate to
3.
the I/O connectivity base, and then remove the bottom plate from the I/O connectivity base (2).
Adjust the voltage select switch behind each serial port to the appropriate setting.
4.
Configuring the I/O connectivity base's powered serial ports 25