I usually leave my monitor on 24/7, but have recently noticed that after leaving it off for an hour or so and turning it back on the display is darker on the top right side. I also noticed that after the monitor warms up everything seems to go back to normal once I turn it off then on again. This issue happened a year back as well but I didn't pay it any mind thinking it could possibly be something else. I can turn the monitor off and on over and over and the screen is fine with no darkening, but if I leave it off for an hour and turn it on the screen is sometimes dark. Any suggestions as to what I should do about it?