"It is a color raster scanned display. "

How could you read my post and not realize that I know that ?

"OP should read up on the color display
adjustments and go through the procedure."

Why ? To **** it up ? When you have a fault the LAST thing you do is adjust.. He should CHECK the geometry. In a raster scanned display the geometry is dependent on proper voltage supplies. If the geometry is right, the voltages are right, no matter what the print says.

"If that does not work, a new tube
would be the next thing."

Sure, Keysight has them on the shelf right between the hen's teeth and the philosopher's stones.

"There might even be a LCD upgrade available for
less than a new tube. "

What planet are you from ? Are you saying that they would engineer a Tcon board and backlight assembly for an old obsolete piece of equipment they no longer support ? You'll get that right after world peace.

"We still do not know what the power supply is doing. "

If the geometry is right, it is doing what it has to do.

"I bet a simple adjustment of the screens on the CRT would get some more
years out of it. "

Know much about CRTs ? Sure turning up the G2, which will be common to all three guns is likely to get a more usable brightness level. However, this type of video drive might start (or accelerate) the cathode stripping process.

The best bet is to increase the filament supply. Usually 10 - 20 % will do it, and it usually will last. Rejuvination might cause a G1-K short.

It can be run that way but with the likely bandwidth the circuit will have to be modified to overpeak the video output. I have done this a few times. First the G1 is tied to the K through a resistor, high enough not to cause damage due to the filament voltage but low enough that it is coupled to the cathode which stabilizes the frequency response. Then a proper location in the circuit for a peaking cap must be chosen, and of course its value. For this I would need a real print, not one of those enhanced block diagrams which seems to be the only thing I can get.

With a real print I can give more details on what to do. I am very experienced at extending the life of color CRTs, did it for decades. But this overpeaking stuff only applies if there is a short in the CRT. Most of the time it just works.

HAHA, an LCD refit for a color CRT. Thanks for the laugh.

The emgineering cost would exceed the value of the whole unit. That is before one such modification is produced. What's more, if it is a Trinitron it is a bit easier because it has a cylindrical curvature on the screen. A curved LCD screen is expensive, even if it is only curved on one axis.

Yup, be sure to let us know when you got that space/time continuum thing beat. I think ole' Bert Einstein was holding out on us.