3.4 Preparing the Motherboard for Installation
3.4.3 Motherboard jumpers
Hardware settings are made using mini jumper connectors on the motherboard. Jumpers are devices that bridge pins on circuit boards. Closing or opening the circuits establishes logic levels to select functions for the operation of the board. Data generally does not travel through these circuits. Most of the jumpers will correlate to the CPU.

Typically, motherboard jumpers are configured by using a jumper to bridge a pair of pins that are to be connected together (to complete a circuit) on the board. Removing or inserting jumpers on a set of pins will enable or clear a given option, as specified in the motherboard manual. For all settings, it is recommended that the instructions found in the motherboard manual be followed closely. Table shows an example of how this information is presented in the manual. Remember that the jumper specifications for any board are provided by its manufacturer; they are not necessarily the same as those found in this table.

Caution: Do not move any of the jumpers with the power on. Always turn off the power and unplug the power cord from the computer before changing jumpers.

Other Jumpers
Several other jumper settings may have to be set along with the general motherboard configurations. These are summarized as follows:

  • BIOS recovery – This jumper is for recovering BIOS data from a diskette in the event of a catastrophic failure. Leave this to the default (normal operation) values. Check the technical product specifications for details.
  • Clear CMOS – This jumper, when provided, is used to reset the CMOS settings to the default values. This procedure must be done each time the BIOS is updated.
  • Password clear – Use this jumper, if provided, to clear the password if the password is forgotten. The default setting is usually password enabled.
  • BIOS setup access – This jumper enables or disables access to the Setup program. The default setting is access enabled.
  • Processor voltage – This jumper (or jumpers), when provided, sets the output of the onboard voltage regulator. The two choices are usually standard voltage or VRE.

Caution: When installing a processor in the motherboard for the first time or upgrading to a new processor, check the processor documentation for the correct voltage setting. Operating the processor at the wrong voltage can cause unreliable performance or damage.