HP Rp3000 - Point of Sale System Hardware Reference Manual page 40

Figure C-4
Item
1
2
To configure power to the serial ports:
1. Remove/disengage any security devices that prohibit opening the computer.
2. Remove all removable media, such as compact discs, from the computer.
3. Turn off the computer properly through the operating system, then turn off any external devices.
4. Disconnect the power cord from the power outlet and disconnect any external devices.
CAUTION:
long as the system is plugged into an active AC outlet. You must disconnect the power cord to
avoid damage to the internal components of the computer.
5. Remove the computer cover.
34 Appendix C Powered Serial Ports
Powered Serial Port Expansion Card Jumper Locations
Jumper
J4
J5
Regardless of the power-on state, voltage is always present on the system board as
Port Name
COM 3
COM 4
ENWW