Monitor cable is unlikely.... highly unlikely. Unless it's been chewed on by an animal. It is possible that, like VoidHawk just mentioned, it could
be issues with the backlight. It could also be capacitors dying, especially if it's seen a lot of on time. in four years.
Thank you to everyone who took part in trying to help me figure out what is going on. It is the light in the monitor that is the problem. I just wish
I didn't have to toss it & get a new one. I miss the days of things being built to last, now it's life expectancy is hardly anything so when the
newest model comes out, you have to buy it.