Dell OptiPlex Gn Diagnostics and Troubleshooting Guide (.pdf) - Page 59

subtests check the storage capability of a drive as well as the hard-disk drive controller (which affects the ability to read from and write to the drive). The subtests are for all hard-disk drive types except for small computer system interface (SCSI) drives. To test SCSI drives, use the SCSI Devices Test Group. Subtests The five subtests in the Hard-Disk Drives (Non-SCSI) Test Group confirm the following drive functions: • Disk Controller Test Checks the internal microcode of the hard-disk drive controller • Forced Error-Correction-Code Test Checks the ability of the hard-disk drive to identify and correct errors • Seek Test Checks the drive's ability to search for a specified track on the drive and to position the read/write heads of the drive to all tracks • Read Test Positions the read/write heads at each cylinder of the drive for reading data and verifies that all tracks on the drive can be read correctly • Write Test Positions the read/write heads at each cylinder of the drive and verifies that all tracks on the drive can be written to correctly Why Run a Hard-Disk Drives Test? If you check your hard-disk drive to determine the amount of available space, your operating system will probably report problem areas. Problem areas on harddisk drives are common, because most hard-disk drives have a small amount of space that is not usable. The harddisk drive keeps a record of this space so that your computer will not attempt to use it. Identification of unusable disk space, unless it is an unusually large amount (over five percent of the possible total), should not be regarded as a cause for testing the hard-disk drive. These are the most common symptoms that might prompt you to test the hard-disk drive: • The hard-disk drive fails during the boot routine. • Seek errors are reported by the operating system or application programs. • An error message appears on the screen stating that the computer cannot read from or write to the harddisk drive. • Data on the hard-disk drive is corrupted or lost; these problems may be intermittent. Once saved by a program, files cannot be properly recalled. IDE CD ROM Drives Test Group The subtests in the IDE CD ROM Drives Test Group check the functionality of up to four IDE CD-ROM drives connected to the primary and secondary IDE ports. Before conducting an IDE CD-ROM test, insert a CD with audio and data tracks (such as a multimedia CD) into each CD-ROM drive. NOTES: All of the subtests except for the Audio Output Test require a CD with data tracks. The Audio Output Test requires a CD with audio tracks. If a CD-ROM drive is empty, or if it contains a CD that does not have the required data or audio tracks (depending on the subtest[s] being conducted), the subtest(s) will fail. Subtests The five subtests in the IDE CD ROM Drives Test Group confirm the following drive functions: • Drive Controller Test Causes the drive to execute its internal self-test. • Seek Test Checks the drive's ability to search for each block on the device. • Read Test Positions the read heads at each block of the device for reading data and verifies that all blocks on the device can be read correctly. Running the Dell Diagnostics 4-17