I've got 3 (had 4) NCD 20" monitors. Apparently this is the same as the Hitachi HM-4020-D.
Three of the 3 of the 4 monitors all suffer the same symptoms. They flicker to a yellow tint for a month or so and then go to a permanent yellow tint. I'm guessing there's some flaw in the monitor design that's causing these problems.
It'd be a shame to toss em in the trash. Besides the tint problem they're decent monitors. Anybody got a clue as to what the problem might be and if there's a reasonably economical fix for it?