How to Change the Master/Slave Designation on a Hard Drive

When more than one hard drive is installed on a computer system, each drive competes for control of the computer. To allow both drives to work in harmony on the same computer system, the controlling (or startup) drive is designated the master drive and the other drive is designated the slave drive. You can change this designation. The following procedure applies to any PC-compatible computer.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• Eyebrow Tweezers
• Hard Disks

1. Decide which hard drive will be the startup (master) drive. If this drive was the startup drive previously, or if it's a new hard drive, then the master drive designation will already be set.

2. To change the designation of a new drive to be a slave drive, skip to step 4.

3. To change the designation of an existing drive to be a slave drive: Turn off the computer, unplug the power cord, remove the drive from its drive bay, and disconnect the drive from its power cord and ribbon cable.

4. Check the hard drive documentation or the label on the drive itself for master/slave jumper settings.

5. Find the jumpers on the circuit board of the drive. Jumpers are plastic plugs with metal sleeves that form a circuit between a pair of pins. Jumper locations are labeled on the board with a J followed by a number (such as J20).

6. Use tweezers or very small pliers to remove or reposition the jumpers to the configuration shown in the documentation or on the disk label.

7. Install (or reinstall) the hard drive in the computer. (See "How to Install a Second Hard Drive.")

Tips & Warnings

• Jumpers are very small and easy to lose. Hold your hand over the jumper while removing it to keep it from jumping too far.
• Store jumpers in a small plastic bag for future use.
• Always disconnect the power cable from the computer before handling the drive to prevent electrical shock.
• Always ground yourself and your tools by touching a safe metal surface (such as the computer cover or frame) before handling the hard drive to prevent damage to the electrical components.
• Avoid touching the pins with the tweezers or pliers to keep from bending the pins.

on 11/22/2005 Usually the diagram for jumper settings (Master/Slave) are printed on the hard drive.
Draw a copy of these to keep so that if you need to change the jumper, you can do so without removing the drive to see the diagram.