This section provides procedures for removing and replacing the components,
assemblies, and subassemblies in the Dell Precision� 450 computer and Dell
Precision 650 computer. Unless otherwise noted, each procedure assumes that the
following conditions exist:
Your computer is primarily a tool-less one, but certain procedures (such as
removing the heat-sink blower or the control panel) require the use of one or
more of the following tools:
Small flat-blade screwdriver.
#1 and #2 Phillips-head screwdrivers.
An 8-inch, #2 Phillips-head screwdriver.
It is recommended that you use a wrist grounding strap as explained in "Precautionary
Measures."
Use the following safety guidelines to help protect your computer from
potential damage and to ensure your own personal safety.
CAUTION: Before
you begin any of the procedures in this section, follow the safety
instructions in the System Information Guide.
CAUTION: Do not
attempt to service the computer yourself, except as explained in your
online Dell� documentation or in instructions otherwise provided to you
by Dell. Always follow installation and service instructions closely.
NOTICE: To help
avoid possible damage to the system board, wait 5 seconds (or wait until
the standby light is extinguished) after turning off the computer and
unplugging the power cable before removing a component from the system
board or disconnecting a device from the computer.
Before you start to work on the computer, perform the following steps in the
sequence listed:
Shut down the computer through the Start
menu.
Ensure that your computer and attached
devices are turned off. If your computer and attached devices did not
automatically turn off when you shut down your computer, turn them off now.
NOTICE: To
disconnect a network cable, first unplug the cable from your computer and
then unplug it from the network wall jack.
Disconnect any telephone or
telecommunication lines from the computer.
Disconnect your computer and all attached
devices from electrical outlets, and then press the power button to ground
the system board.
In addition, take note of these safety guidelines when appropriate:
When you disconnect a cable, pull on its connector or on its strain-relief
loop, not on the cable itself. Some cables have a connector with locking
tabs; if you are disconnecting this type of cable, press in on the locking
tabs before disconnecting the cable. As you pull connectors apart, keep them
evenly aligned to avoid bending any connector pins. Also, before you connect
a cable, ensure that both connectors are correctly oriented and aligned.
Handle components and cards with care. Do not touch the components or
contacts on a card. Hold a card by its edges or by its metal mounting
bracket. Hold a component such as a microprocessor chip by its edges, not by
its pins.
Static electricity can harm delicate components inside your computer. To
prevent static damage, discharge static electricity from your body before you
touch any of your computer's electronic components, such as the microprocessor.
You can do so by touching an unpainted metal surface on the computer chassis.
As you continue to work inside the computer, periodically touch an unpainted
metal surface to remove any static charge your body may have accumulated.
You can also take the following steps to prevent damage from electrostatic
discharge (ESD):
When unpacking a static-sensitive component from its shipping carton, do
not remove the component from the antistatic packing material until you are
ready to install the component in your computer. Just before unwrapping the
antistatic packaging, be sure to discharge static electricity from your
body.
When transporting a sensitive component, first place it in an antistatic
container or packaging.
Handle all sensitive components in a static-safe area. If possible, use
antistatic floor pads and workbench pads.
