How to Set Jumpers and Dip Switches on a Motherboard
Jumpers and Dip switches are used on motherboards to configure settings according to information that is supplied in the motherboard's user manual.
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Close-up views of a block of jumpers ( above left) and two blocks of DIP switches ( above right) found on most motherboards.
Below is an image of an individual jumper showing its top and bottom. The wire crosses over the top. The jumper must be fitted so that the flat bottom makes connection with the surface of the motherboard, as shown in item 2.7 below.
A jumper can cover two metal pins. Two uncovered metal pins can clearly be seen protruding vertically from the surface of the motherboard in the image of a block of jumpers on the left.
When a jumper fits over two pins, it shorts a connection and enables an option - as illustrated and explained in the motherboard's user manual. All of the major motherboard manufacturer's make user manuals availableas downloads, usually in the PDF format.
The image below shows a jumper placed over two pins on a desktop-PC motherboard. A particular jumper setting makes its possible for the BIOS settings to be retained by allowing the CMOS battery to give power to the small amount of RAM memory that holds them. Placing the jumper over the two jumpers that are behind the jumper shown in the image cuts that power and removes the BIOS settings. It might be necessary to make use of this feature if you have set incompatible BIOS settings that can render the computer unbootable - or something else has gone wrong with the settings. Only the current BIOS settings that the computer has been using are cleared, not the main settings, which are permanently placed into flash memory when the BIOS chip is flashed. (The BIOS can be reflashed with an updated file.) Unlike RAM memory, flash memory holds data without being powered. When the PC starts up and tries to access the BIOS settings, it finds none if the BIOS has been cleared by the reset jumper setting and it makes the BIOS copy the default settings from the flash memory into the RAM memory that is kept alive by the CMOS/BIOS battery. By placing the jumper over the two pins that allow the CMOS battery to power the CMOS chip that holds the settings, customised settings are retained. Removing the CMOS battery also removes the current settings. Any customised settings are lost. The CMOS/BIOS battery is shown on the left.
MSI provides excellent user manuals in the PDF format. Visit msi.com and look under the motherboards or mainboards products. At the time of writing (June 2009), the motherboards will be shown as Socket LGA775 and Socket LGA1366 for Intel processors, or Socket AM2+ and Socket AM3 for AMD processors.
If a jumper is left hanging on one pin, or two pins are left unjumpered, the option is left open and is therefore not enabled.
DIP switch settings have On and Off switches that operate in the same way as a light switch. The On position is marked. The Off position is usually the opposite of the On position. You should use a screwdriver with a small head, or a pair of tweasers to move the switch into the On or Off postition.