However, the display has now gone completely haywire. Yesterday afternoon the display began to 'shake' more than before, then lines of colour appeared all over the place and finally vertical bands of black, red, blue and yellow.
I tried the obvious rebooting but it didn't fix the problem. So I got out an
old CRT monitor and connected that to the PC instead and that worked ok.
To start with the disconnected digital display had a 'snowstorm' screen and bands of colour but after about half an hour the display changed to the 'no connection - check signal cable' message - just like normal when the cable is disconnected.
Today I tried again first thing with the Samsung display and all appeared to work well for about half an hour. However, the screen display then began to break up more and more until it was completely disrupted - just like yesterday (and I returned to my old CRT monitor again).
Once disconnected the digital display again had a very lined and broken up display but having now cooled down (for about 15 minutes) it has returned to a clear picture of the 'no connection - check signal cable' message.
So it looks as if it is an intermittent thermal fault in the display
itself, linked to how long it has been connected to the pc.
Has anyone else experienced the above, and any suggestions please?