With the back of you hand lightly against the screen, turn it on and off a few times. Feel the hair on your hand "tingle" a bit from static electricity? If no, then probably flyback trouble.
As said above, but do also check if turning the picture width/height adjustments on the rear of the monitor have any effect. In my 1084S the V.HEIGHT potentiometer on the rear had a broken soldering causing the screen to be powered on but without any picture shown. Cracked solderings on the inputs can also cause blank screen so try fiddling the connectors while power on to see if there is any life.
