Acer S240HL - Manual (Page 25)

EN-16
(DVI/HDMI Mode)
Problems Current Status Remedy
No Picture LED ON 
Using OSD, adjust brightness
and contrast to maximum or
reset to their default settings.
LED OFF 
Check the power switch.

Check if AC power cord is
properly connected to the
monitor.
LED displays amber color 
Check if video signal cable is
properly connected at the back
of monitor.

Check if the power of computer
system is ON.