I just started having this problem as well. TV shuts off screen, standy light blinks green for about 30 seconds. then screen turns back on. at this point, I am getting this happening every 5-10 minutes! I have unplugged the tv from the power strip, waiting 20 minutes, plugged it directly into the wall outlet.
nothing seems to work.
checked error codes, nothing but zeroes... so calling a tv repair shop to come out and see if they can figure what the deal is.
have not tried to clean the rear fan blades as others have done.. yet, will try that and let you know.
but right now, I'm at 5 minute intervals of screen shutdown... this sucks.