Checking jumper settings
On an IDE hard disk, one or more jumpers on the drive must be set to determine its Master/Slave status. This setting isn’t usually an issue in an existing hard disk installation that suddenly doesn’t work anymore, but it can cause problems when you move a drive from one PC to another.
Depending on the drive, the following jumper settings may be available:
- Single--Use this setting when the drive is the only one on that IDE subsystem; that is, the only one on that ribbon cable. Not all drives have a Single setting; if there is none, use the Master setting instead.
- Master (MS)--When there are two drives on the IDE subsystem and the other drive’s jumpers are set to Slave, or if this is the only drive on the subsystem and it doesn’t have a separate Single setting, use this setting.
- Slave (SL)--Use this setting when there are two drives on the IDE subsystem and the other drive’s jumpers are set to Master.
- Cable Select (CS)--If you are using a cable that relies on the device positioning to determine its Slave/Master status, use this setting. This setting is uncommon.
Checking SCSI termination
If the machine uses a SCSI drive, there are two factors with which to be concerned: termination and ID. These settings are not an issue when troubleshooting a drive that has suddenly gone bad in an existing system, but if you are moving a drive from one system to another and it doesn’t work in the new system, improper SCSI settings may be the culprit.
If this is the last SCSI device in the chain, it must be terminated. Termination methods vary. On some devices, you set termination with an extra jumper; on others, you use a cap or plug over a connector. On most hard disks, you terminate using a jumper setting.
SCSI-based drives usually have jumpers just like ATAPI ones, but instead of setting the Master/Slave status, they assign a SCSI ID number to the device. Some SCSI devices have a wheel or button instead of jumpers with a little window indicating the setting, but this is uncommon on a hard disk.
There can be up to seven SCSI devices on a single narrow SCSI bus, and up to 15 devices on a wide SCSI bus. There are either eight or 16 addresses in total, depending on your system. The host adapter takes one of those addresses, leaving seven or 15 for the remaining drives. Usually, the host adapter claims the highest number for itself.
The SCSI ID comes from a binary representation of the jumpers. For example, on a device with three SCSI jumpers and all of them are without jumper settings, the ID would be 000b (b stands for binary here), or 0. An ID of 001b would be 1; 010b would be 2; and so on.
The problem lies in the fact that some manufacturers set the jumpers to read from left-to-right, while others use right-to-left. So on one drive, the leftmost jumper set would be 1, while on some other drive, the rightmost jumper set would be 1. Check the drive’s label for information about which way the drive works. If all else fails, try the manufacturer’s Web site.
2. Checking BIOS setup (IDE only)
In most modern systems, the BIOS can automatically detect your hard disk, so no special BIOS setup is required. However, if you are working with an older or quirky BIOS, you might need to enter the BIOS setup program and change the drive’s IDE channel (such as Primary Master or Primary Slave, for example) from None to Auto so the BIOS will attempt to find and identify the drive.
On an old BIOS, you occasionally may need to select User as the drive type and manually enter the drive’s settings. Automatic detection of IDE devices was part of the ATA-3 standard, released more than 10 years ago, though, doing so would be rare.
Some BIOSs also have a separate Detect IDE Devices utility built in. If the BIOS contains such a utility, you can use it to prompt the BIOS to detect the new hard disk. This comes in handy when you aren’t sure whether or not the drive is working, because you can get an answer immediately rather than rebooting and waiting to see whether the BIOS finds the drive on startup.
3. Virus checking
If you’ve come this far in the troubleshooting process and the drive still isn’t working, check for viruses. A drive containing a boot-sector virus will not only malfunction, it can spread the virus to the disk you boot from, such as your emergency startup disk.
On a system that you know is good and that has an antivirus program installed, update the virus definitions, and then make a virus-checking boot disk. Write protect it, and then use it to start the system containing the nonworking hard disk and check it for errors. If the drive is not partitioned and formatted, the boot disk might not be able to check the data area of the drive. That’s okay for now; just let it get as far as it can before moving on to the next step, checking the partition.