Preparation For Disassembly - HP dx2420 - Microtower PC Service & Reference Manual

Preparation for Disassembly

See Identifying the Chassis, Routine Care, and Disassembly Preparation on page 19
procedures.
1. Remove/disengage any security devices that prohibit opening the computer
Devices on page
2. Close any open software applications.
3. Exit the operating system.
4. Remove any diskette, compact disc, or media card from the computer.
5. Turn off the computer and any peripheral devices that are connected to it.
CAUTION:
Regardless of the power-on state, voltage is always present on the system board as long as the
system is plugged into an active AC outlet. In some systems the cooling fan is on even when the
computer is in the "Standby," or "Suspend" modes. The power cord should always be disconnected
before servicing a unit.
6. Disconnect the power cord from the electrical outlet and then from the computer.
7. Disconnect all peripheral device cables from the computer.
8. Lay the computer down on its side to achieve a safe working position.
NOTE:
Keep all screws with the units removed.
CAUTION:
screw in an application may damage the unit.
28 Chapter 6 Removal and Replacement Procedures Microtower (MT) Chassis
29).
Turn off the computer before disconnecting any cables.
During disassembly, label each cable as you remove it, noting its position and routing.
The screws used in the computer are of different thread sizes and lengths; using the wrong
for initial safety
(External Security