i have the same prob... monitor wasnt actually turning off...
the backlight was switching off making the screen go black giving the impression the monitor was in standby... when you shined a torch into the screen you could still see the desktop and everything on it...
this can be fixed by either replacing blown capacitors (look like cylindrycal batteries) on the power supply board (if they look rusty and bulged out at the top)
or in my case by replacing the "inverters" or if you are no good at soldering stuff you can buy the whole new power supply board for 29 dollars and simply remove the screws holding the old one down and screw the new one in... hey presto... nice working monitor as good as new.
culdypete
November 2008