Problem with color smear

[Mario]

I read past messages regarding color smear, but I didn't get enough info to really zero in on my problem.

I have a WG 25K7194 monitor. The red color is very dim, and I'm trying to get a better picture. I tried adjusting the drive and cutoff POTs, but the only way I could get a color-balanced pic is when the brightness is really dim. I figured out that as I increase the brightness, the red color "smears" to the right, effectively spreading out so that it is overpowered by the blue and green colors.

I also have a WG25K7191, and this monitor has a similar problem, but it is the green color that is smearing.

Can someone please explain what is causing the color smearing, and how do I correct it?

I assume that a cap kit is in order. But the 7194 monitor was supposedly recapped recently. Is there a specific cap that may need replacing?

Thanks for any help.

Mario

[Ken Layton]

The contrast control is turned up too high.

[Mario]

The contrast control is turned up too high.

I played around some more, and I don't think it's the contrast. I lowered the contrast and still couldn't get the display correct.

Here's some more info:

I found out that the smear is due to the fact that the red drive pot was set really high. If I set the other color's drive to high, they smear as well. So, I lowered all of the drive settings.

But, the red color is too dim.

[Ken Layton]

If turning the red CUTOFF pot up doesn't help then the red gun is weak. You'll need to put the tube on a rejuvenator to fix that.

[Mario]

If turning the red CUTOFF pot up doesn't help then the red gun is weak. You'll need to put the tube on a rejuvenator to fix that.

I was afraid it would be something which I don't have the power to fix. I hope it's not too expensive.

As I asked before, can you  explain exactly what the "drive" and "cutoff" pots are controlling? I assume the "drive" controls the intensity of the particular color, but what does cutoff do?

Thanks for all of your help.

Mario

[Ken Layton]

In a nutshell and boiling it down to simple terms, Drive is "coarse" color control (for the particular color) and cutoff is "fine" color control.

[paigeoliver]

Aw nuts, I have a couple of red smearing monitors that won't adjust out. =(

[Ken Layton]

On Wells 7000 series monitors you need to keep the contrast control turned down or you'll never be able to adjust the color smearing.

Otherwise for other monitors if the colors won't adjust (and you've already done a capkit) then you have a tube that needs rejuvenation.

[Mario]

Aw nuts, I have a couple of red smearing monitors that won't adjust out. =(

One of my smearing monitors is going into a MAME cab with an ArcadeVGA. I used the AVGA's drivers to up the brightness instead of using the monitor's controls. Using this and the "screen" knob on the black thing on the monitor board (sorry, I don't know the technical name), I found that I can get the brightness upped a bit without the smearing, making a better looking screen. It's definitely not the best, but it's better than what I had before.

Mario