(^630) PC Hardware: A Beginner’s Guide
Troubleshooting Hard Disk Drives
When a hard disk error occurs, it is usually a cause for real concern. Not only will the PC
not boot, but there is the threat that all your data and programs could be lost. A hard disk
problem can be caused by the hard disk drive, the hard disk controller, a SCSI host
adapter, cabling, and in many situations, the power supply.
There is always the risk when troubleshooting a hard disk drive that any data stored
on it could be destroyed. This is why you should always create and verify a full backu pof
the hard disk before you begin to work. To verify a disk backup, restore a few random
files from it. All of this assumes that you can access the disk drive to make a backu por to
perform troubleshooting.IDE Hard Disk Drives
Most current PC motherboards include support for either one or two IDE/ATA (Inte-
gratedDriveElectronics/ATAttachment)channels.EachIDE/ATAchannelsupportsup
to two disk drives, which must be designated with one as a master and one as a slave.
On an IDE/ATA disk, the designation of master represents disk0; slave indicates disk1.
Neither is actually in charge of the other. The BIOS uses the disk0 and disk1 designations to
assign logical device names (C:, D:, etc.) to disks. The master on the primary channel is as-
signed a drive letter first (typically C:), followed by the primary slave, and the master and
slave, if any, on the secondary channel. Disk0 is typically the boot drive.
Themaster/slavedesignationissetwithajumperonthediskdrive.Figure24-2showsthe
jumpers from a typical hard disk drive, and Figure 24-3 illustrates the jumper positions used
toconfigurethedevice.ThetwoIDE/ATAdrivesonachannelareconnectedtothesamedata
cableinseries.Itdoesn’tmatterwhichdriveisdesignatedastheslaveorthemaster.SeeChap-
ter 9 for more information on hard disk drives and their jumper settings.
To begin troubleshooting any disk drive problem, you should boot the system from a
floppy disk drive. The AUTOEXEC.BAT and CONFIG.SYS files on the boot disk shouldFigure 24-2. Jumpers on a hard disk drive