Dell XPS H233 manual Unpacking Your Hardware Option, Internal Components, Jumpers, Switches

Unpacking Your Hardware Option

When you remove an option from its shipping carton, you may find it wrapped in antistatic packing material designed to protect it from electrostatic damage. Do not remove the packing material until you are ready to install the option.

CAUTION: See “Protecting Against Electrostatic Discharge” in the safety instructions at the front of this guide.

For instructions on performing a particular upgrade, see your online System User’s Guide.

Internal Components

Figure 3-2 shows the desktop chassis with its cover removed, and Figure 3-3 shows the mini tower chassis with its cover removed. Refer to the appropriate illustra- tion to locate internal features and components.

When you look inside your computer, note the direct cur- rent (DC) power cables coming from the power supply. These cables supply power to the system board, to inter- nal drives, and to certain expansion cards that connect to external peripherals.

The flat ribbon cables are the interface cables for internal drives. An interface cable connects a drive to an interface connector on the system board or on an expansion card.

The system board—the large printed circuit board mounted vertically in the bottom half of the mini tower chassis or secured to the bottom of the desktop chassis— holds the computer’s control circuitry and other elec- tronic components. Some hardware options are installed directly onto the system board.

During an installation procedure, you may be required to change a jumper setting on the system board and/or a jumper or switch setting on an expansion card or on a drive. Jumpers and switches provide a convenient and reversible way of reconfiguring the circuitry on a printed circuit board. For information on jumpers and switches, see the next two subsections, “Jumpers” and “Switches.”

Jumpers

Jumpers are small blocks on the system board with two or more pins emerging from them.

Plastic plugs containing a wire fit down over the pins. The wire connects the pins and creates a circuit.

To change a jumper setting, pull the plug off its pin(s) and carefully fit it down onto the pin(s) indicated.

CAUTION: Make sure your system is turned off before you change a jumper setting. Otherwise, damage to your system or unpredictable results may occur.

A jumper is referred to as open or unjumpered when the plug is pushed down over only one pin or if there is no plug at all. When the plug is pushed down over two pins, the jumper is referred to as jumpered. The jumper setting is often shown in text as two numbers, such as 1-2. The number 1 is printed on the circuit board so that you can identify each pin number based on the location of pin 1.

Figure 3-5 shows the location and settings for the system board jumpers in your computer. See Table 3-2 for the designations, default settings, and functions of your sys- tem’s jumpers.

Switches

Switches control various circuits or functions in your computer system. The switches you are most likely to encounter are dual in-line package (DIP) switches, which are normally packaged in groups of two or more switches in a plastic case. Two common types of DIP switches are slide switches and rocker switches (see the following illustration).

Inside Your Computer 3-3