S2415H, severe screen flicker/shudder

I have a S2415H Monitor plugged into my Inspiration 5567 laptop. Over the last few months what started as a screen flicker that went away after a couple of minutes has now developed into a continuous severe flicker that is best described as a 'shudder' making it not fit for purpose. The laptop screen is OK and I do not have any problems when I plug the laptop into other monitors. The problem remains on the S2415H Monitor when it is connected to other computers, even using the VGA port, and  is still present when all connecting cables are removed and the monitor is in auto test mode. I suspect that I have a faulty monitor. Can anybody help please?