Epson EL 486UC - Manual (Page 104)

The powerswitch is on but the powerlight is not on.
Turn off the monitor’s power, wait five seconds, and turn it
back on.
If the light still does not come on, check the electrical outlet for
power. Turn off your monitor and unplug it from the outlet.
Then plug a lamp into the wall outlet and turn it on. If the light
turns on, your monitor may be faulty.
Diskette Problems
You see a diskette error message.
Reinsert the diskette, making sure you insert it all the way. If
the drive has a latch. turn it down to secure the diskette.
Also, check to see that you have inserted the right type of
diskette in the drive. For example, make sure you are not
inserting a high-density diskette in a double-density drive.
If reinserting the diskette does not solve the problem, insert the
diskette in another diskette drive of the same type. If you can
read the diskette in a different drive, your drive may be faulty.
The diskette is the tight type, but you still see an error
Check that the diskette is not write-protected, preventing the
drive from writing to the diskette.
Make sure the diskette is form atted. See your operating system
documentation for instructions on formatting diskettes.
You may have set the Diskette Access option in SETUP to
Supervisor but have logged onto your system using a User
level password. See Chapter 2 for information about setting the
D i s k e t t e A c c e s s o p t i o n a n d u s i n g S u p e r v i s o r a n d U s e r
passwords.
6-6 Troubleshooting