Acer AR380 F1 - Manual (Page 134)

5 System troubleshooting 116
activity indicators for the hard drive(s), DVD-ROM drive, and any other
device you may have installed.
If any of these indicators fail to light up, refer to related problems
listed in the “HDD activity indicator does not light.” on page 117.
Confirming loading of the operating system
Once the system boots up, the operating system prompt appears on
the screen. The prompt varies according to the operating system. If the
operating system prompt does not appear, see "No Characters Appear
on Screen" on page 119.