AMW LCD MONITOR MODEL F199

Have a rather strange problem, for some time now this monitor has had a somewhat random problem where the video will suddenly be swarmed with what looks like multiple vertical lines of different color random noise at which point the whole picture shuts down. Sometimes I got long term relief by playing with the cable from the monitor to my pc. But the problem has now become more frequent and modifications to the cable has no effect. I can shut the monitor down when this happens and sometimes if I restart the picture is fine for a period of time, but eventually the problem occurs. The problem does not appear to be in the main card as I have replaced the main card and the problem persists. Attached is a picture of the power card. Any ideas? Attached also is a picture of the screen just before it goes black.