Epson QX-10 Operation Manual page 13

Once you've powered up the computer, the small red light near
the top right corner of the front of the main unit comes on and
the cooling fan starts up (you can hear it). You may also notice
that a number of small red lights on your keyboard blink on and
off. This indicates that your QX-10 is performing an internal self-
diagnostic test.
The small red light to the right of drive A also comes on, and
the message INSERT DISKETTE appears on the monitor screen.
(If any other message appears, see Chapter 4, "Troubleshooting.")
If the brightness on the screen isn't the way you like it, reach
around to the back of the right side of the monitor until you feel
the control knob near the bottom. Turning the knob clockwise in-
creases the brightness; turning it counterclockwise decreases it.
Experiment a bit to find the most comfortable brightness for you.
Before we go any further, we need to explain the concept of
booting, so let's proceed!
INERT DISKETTE
9