I have a Viewsonic VA1912WB 19" monitor and the screen is black and power light is a solid green. If I keep turning it on and off (like 30 or 40 times), eventually the screen will appear and stay. It takes multiple times to work and it will flicker with brief horizontal lines then go black or appear white then go black or the screen pops on and then goes black. I can see documents in the background, it looks like a black filter is on the screen. Any ideas on how to fix the monitor? Thanks