Dell OptiPlex 990 (Early 2011) - Manual (Page 80)

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.
Time-of-day not set-please run the System Setup program
Description The time or date stored in System Setup does not match the
computer clock.
Timer chip counter 2 failed
Description A chip on the system board may be malfunctioning.
Unexpected interrupt in protected mode
Description The keyboard controller may be malfunctioning or a memory
module may be loose.
WARNING: Dell's Disk Monitoring System has detected that drive [0/1] on the
[primary/secondary] EIDE controller is operating outside of normal
specifications. It is advisable to immediately back up your data and replace your
hard drive by calling your support desk or Dell.
Description During initial startup, the drive detected possible error conditions.
When your computer finishes booting, immediately back up your
data and replace your hard drive (for installation procedures, see
"Adding and Removing Parts" for your computer type). If no
replacement drive is immediately available and the drive is not
the only bootable drive, enter System Setup and change the
appropriate drive setting to None. Then remove the drive from the
computer.
Write fault
Description The operating system cannot write to the floppy or hard drive.
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