CRT Tube Gun Controls Touchy

[vol.2]

I have an NOS Sony monitor from the late 80s (CDP-9000, RGB/RGBI) that I just did a full setup on, and I noticed a very peculiar behavior of the color Drive and Bias controls.

Basically, there is no issue with the tube itself I can see, but the position of the drive and bias controls is extremely sensitive (way more than I have ever seen). I was finally able to get the white balance dialed in, but it took what felt like ages of turning the pots just the tiniest amount to keep them from going way too high or way too low. The blue and red seemed to be much worse than the green.

I haven't replaced any caps because the geometry is more or less fine (the sides are a very small amount wavy), and it seems to be getting better the longer I run it, which makes me think it just never got burned in enough from the factory.

My current thought is that maybe the specific drive and bias pots are slightly damaged from being in the same spot for so long and then changed, although I did clean them with Caig Faderlube (green stuff), so they *should* be good.

I guess I can just buy some pots with more turns and hopefully the added travel gives me enough wiggle room to dial things in more easily

Though I also thought maybe it's an issue with the Screen and Contrast position VS the drive/bias.

Anyone have any ideas?

Thanks

[DejahThoris]

The pots need to be cleaned/lubed or replaced. That's all. See it all the time in arcade monitors.

[vol.2]

The pots need to be cleaned/lubed or replaced. That's all. See it all the time in arcade monitors.

Yeah, was figuring that had to be it, but I thought it was weird that they aren't working on such a new set

I think I'm going to get some pots that have more turns so i can dial things in better