The video is slowly sinking into the blacklevel!
The brightness and contrast controls are at max.

With contrast & brightness set central the screen is
almost black.

Need to check the tube voltages and/or recalibrate
the blacklevel.

Picture geometry and focus are still perfect.

Thanks for any help, Ant

My Viewsonic E790 is fading into darkness as well! If you figure out how to fix this, please let me know!

Thanks a bunch!

You need to check heater voltage, G1 and G2, and rgb cathode values - if all check okay, the crt may be tired.

This is precisely what I was going to do first.
What are the expected voltages?

I was kinda hoping to get this from schematics.

I think it's unlikely the CRT is tired. It's 3
years old. This PC is used at home, it doesn't
get the same level of use as company PCs, never
seen them "get tired". Some of those are left on
24/7. I had the same TV for 15 years (still got
it, still works).

I don't think the emission is low otherwise
it would not be possible to get acceptable
brightness whites with the OSD sliders at max.

Ant

My E790B is also doing this. At first it was a yellowish hue on the screen. Now my contrast and brightness are maxed. I went and bought another monitor. Did you find a fix for this? I have searched all over the net for answers, and no luck. Any help would be much apperciated.

My PS790 also changing brightness if picture content change. So if picture is white tube go dark and if picture is dark tube increase brightness.

Anyone had this problem?