HP Compaq dx7300 ST Hardware Reference Manual page 26

CAUTION
board as 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. If the computer is on a stand, remove the computer from the stand.
6. Remove the computer cover.
CAUTION
between the DIMM sockets. If the LED is illuminated, the system still has power. Turn off
the computer and remove the power cord before proceeding.
7. Locate the correct vacant expansion socket on the system board and the corresponding expansion
slot on the back of the computer chassis.
8. Release the slot cover retention latch that secures the PCI slot covers by lifting the green tab on
the latch and rotating the latch to the open position.
Figure 2-8
9. Before installing an expansion card, remove the expansion slot cover or the existing expansion
card.
20 Chapter 2 Hardware Upgrades
Regardless of the power-on state, voltage is always present on the system
After removing the computer cover, look for the LED on the system board
Opening the Expansion Slot Retainer
ENWW