In electronics and particularly computing, a jumper is a short length of conductor used to close, open or bypass part of an electronic circuit. They are typically used to set up or configure printed circuit boards, such as the motherboards of computers.
Jumpers consist of a set of small pins that can be covered with a small plastic box. Jumpers may look beside the pci slots and near the CMOS battery. In the picture jump pins 1-2 for Normal mode, 2-3 for config mode, and when open the computer is in recovery mode.
How to use the jumper to reset the BIOS:1. At first disconnect the power cable and monitor, open cabinet plate and idintify the jumper block on motherboard.
2. Remembering which two pins are covered, remove the jumper from those pins.
3. Reinstall the jumper in a different position. For example, if you removed the jumper from pins 1 and 2, reinstall the jumper over pins 2 and 3.
4. Replace the cabinet cover and reconnect the power cable and monitor.
5. Turn on the computer and wait 5 seconds. Then press and hold the Power button until the computer turns off again.
6. Disconnect the power cable and monitor again.
7. Replace the jumper over the original 2 pins.
8. Replace the computer cover.
9. Reconnect the power cable and other connections and turn on the computer.
You have now successfully reset your BIOS setting.
Jumper setting in hdd and dvd writer:
| Jumper Position | Performs As |
| 7,8 | Master or single drive |
| NA | Drive is a slave |
| 7,8 & 5,6 | Master with a non-ATA compatible slave |
| 5,6 | Enable cable select |
