Dell OptiPlex 990 (Early 2011) - Manual (Page 83)

Read fault
Description The operating system cannot read from the floppy or hard drive, the
computer could not find a particular sector on the disk, or the requested
sector is defective.
Requested sector not found
Description The operating system cannot read from the floppy or hard drive, the
computer could not find a particular sector on the disk, or the requested
sector is defective.
Reset failed
Description The disk re-set operation failed.
Sector not found
Description The operating system cannot locate a sector on the floppy or hard drive.
Seek error
Description The operating system cannot find a specific track on the floppy disk or
hard drive.
Shutdown failure
Description A chip on the system board might be malfunctioning.
Time-of-day clock stopped
Description The battery might be dead.
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